Mark Spain vs Opendoor: One Buys Your House, One Does Not

How this was sourced. Facts verified against Mark Spain’s own explanation of the Guaranteed Offer and Opendoor’s help center on September 9, 2026. Both companies change terms without notice — confirm anything that matters directly with them before you decide, and hold Zoom Casa to exactly the same standard.

Start here

These are not two versions of the same thing.

The search implies a straight choice between two companies that both make cash offers. They do not. Mark Spain Real Estate says it as clearly as anyone could want: “Mark Spain Real Estate is not buying your home”. It is a licensed brokerage. Your agent assesses the house, takes it to what they call a network of pre-market buyers, and brings back competing offers for you to choose from.

Opendoor is the buyer. It prices the house, purchases it with its own money, and resells it. There is no network and no shopping around, because Opendoor is the counterparty.

So one of these companies is standing next to you and one is standing across the table. That is a genuine difference in whose interests are aligned with yours — and it also means the two are not necessarily alternatives at all. Mark Spain names Opendoor as one of its buyers: “We have strong relationships with buyers like Opendoor because of the volume of properties we bring them.” It is entirely possible to go through Mark Spain and sell to Opendoor.

The trade that follows is the honest one. A brokerage running a competitive process can surface a better number than a single buyer, and Mark Spain says it takes no referral fee from investors, which removes one obvious conflict. What you give up is knowing who you are dealing with in advance: the terms come from whichever buyer wins, and those buyers’ fees are acknowledged and never published. With Opendoor you know exactly who is on the other side from the first minute, and you know their process — but you get one number from one company, and they do not publish what they charge either.

Side by side

What each company actually says.

Read the first row before the rest. A table implies the columns are like-for-like, and in one important way they are not.

	Mark Spain	Opendoor	Zoom Casa
What the company is	A licensed real estate brokerage. Its own page says so plainly: “Mark Spain Real Estate is not buying your home” — the agent takes the house to “our network of pre-market buyers” and brings back competing offers.	The buyer. Opendoor purchases the home directly, then resells it on the open market.	The buyer, with the resale attached. Zoom Casa purchases the home, resells it, and returns the remaining balance to you.
Who ends up owning your house	A third party from their buyer network — local investors, institutional buyers, or “home partner” arrangements. Their own page names one of them: “We have strong relationships with buyers like Opendoor because of the volume of properties we bring them.”	Opendoor.	Zoom Casa, until it resells.
What it costs you	“There are no program fees to participate in the Guaranteed Offer; however, certain buyers in our network may charge fees.” No dollar figure or percentage is published for those buyer fees, and no commission percentage is published for Mark Spain’s own brokerage service.	No fixed percentage published. Opendoor’s help center states outright that it “does not publish a fixed service charge percentage” — the charge “varies and is shown in your offer breakdown,” depending on market, home and conditions.	A single program fee in the 5-10% range, taken out of the resale proceeds rather than paid up front, and itemised on your net sheet before you sign.
Who keeps the resale profit	Not published at program level. One page mentions that “some are home partner arrangements where you can capture additional upside if the home later sells for more on the open market” — no mechanism, percentage or conditions are given anywhere.	Opendoor, on a standard cash offer. Its “Cash Now, More Later” option is the exception: you choose how much cash you take up front, Opendoor renovates and resells, and it says “if there are any profits after fees and costs, 100% goes to your client.” The formula for those profits is not published.	You — the remaining balance comes back to you when the home resells, minus the one program fee.
How the number is produced	A Mark Spain agent visits, assesses the property and takes a video — their 2026 page is explicit that “this first meeting is a conversation, not an inspection.” The property is then marketed to the buyer network, which “typically takes around five business days.”	A questionnaire produces an estimated value in minutes. A home assessment follows — self-assessment photos through the Opendoor Key App (about 30–60 minutes) or an in-person walkthrough (about an hour) — and the final offer is prepared 5–7 business days later. Opendoor states the offer “can go up or down” after the assessment.	Enter an address and see the full net sheet immediately — no email address required, and nothing to accept to see the math.
Repairs	Nothing published about how repairs are handled in a Guaranteed Offer transaction. Their pages warn about other companies demanding “repair credits” after a walkthrough without stating their own rule.	Deducted as a “condition adjustment.” Opendoor is explicit that these “are not quotes from contractors — they are Opendoor’s internal estimates based on the scope of work identified,” and that estimating and deducting is the model rather than asking you to do the work.	Pre-Sale Home Prep can fund the work instead of discounting for it, repaid out of the eventual sale.
Closing timeline	“Close in as little as 21 days,” and several pages say the seller can pick a later date. Some network buyers are described as offering leaseback.	21–60 days, with the seller choosing the date. Opendoor also states that a closing date “longer than 30 days” may incur an extra fee.	as fast as 10–15 days.
Where they work	Five states — Georgia, Tennessee, North Carolina, Florida and Texas — across roughly 15 offices. Which of those markets the Guaranteed Offer itself serves is never stated; eligibility says only “within our service areas.”	Claims the whole contiguous US: “every postal code in the lower 48 states where single-family homes are available.” Two other live Opendoor pages still say “50+ markets” — see the gaps below.	All 50 states + Puerto Rico + DC.
What they will not take	The most specific published list in this comparison: single-family, built after 1950, valued between $50,000 and $1.5M, in their service areas, owner-occupied or vacant, non-distressed, not bank-owned, not in or near flood zones, no non-permitted additions, no significant foundation issues.	No mobile or manufactured homes, no 5+ unit multi-family, no land. Some condos qualify, some do not. No published price floor or cap; age limits “vary by location,” with “pre-1930 in some markets” the only number given.	Typically works with homes in the $300K-$5M range; eligibility is confirmed on the net sheet.
Your agent	Mark Spain is the agent — that is the model. They state: “We never take referral fees from investors, so your agent’s only focus is securing the best outcome for your situation.”	You can bring your own: Opendoor says “your real estate agent can represent you throughout the entire process of selling to Opendoor,” and the agent earns a referral fee at closing.	Your agent stays the listing agent and keeps their full commission. Around 60% of Zoom Casa deal flow comes through partner agents.
What each says you get	Publishes a range for its own program: “75% to 100% of market value through Guaranteed Offer.” That is their claim about their network’s offers, not something we can verify, and it sits oddly next to publishing no fee figure at all.	Publishes no percentage-of-value figure for its own offers, and no typical post-assessment change. Whatever you have read about an average drop did not come from Opendoor.	Up to 85% up front, with the remainder returned on resale — a different shape of number from the two on the left, because it is split across two payments rather than paid once. See the footnote below.

Up to 85% up front, less reserves. The remaining balance (minus a one-time program fee) is paid when the home resells on the open market. Final terms are issued in writing — not all properties qualify.

Sources, in order of first use: Mark Spain on how the program works, Mark Spain on eligibility and buyers, the Guaranteed Offer page, their office list, Opendoor on its service charge, on why an offer changes, on condition adjustments, on the offer timeline, on where it buys, on Cash Now, More Later, and on selling with your own agent.

What we couldn’t confirm

The things other comparison pages make up.

This list is longer than the comparison above, and that is the finding. Two companies asking homeowners for a signature publish remarkably little about what the signature costs. Here are the gaps, left open.

Mark Spain’s own commission or service fee, as a percentage or a dollar figure. It is not published anywhere on their site, for the Guaranteed Offer or for a traditional listing. The percentages on their cost-to-sell articles are industry-general commentary or descriptions of other companies, not their rate.
What the buyers in Mark Spain’s network charge. Their page confirms these fees exist — “certain buyers in our network may charge fees” — and never quantifies them. Since a different buyer wins each house, this may genuinely vary; it is still the number a seller most needs.
Whether you also pay a listing commission on a Guaranteed Offer transaction. No page addresses it either way.
The Guaranteed Offer’s own terms and conditions. Every Mark Spain landing page carries the asterisk “Guaranteed Offers are subject to terms and conditions.” We could not find those terms published anywhere. The only “Guaranteed Offer Terms” section on the site is inside their Terms of Use and is a data-sharing consent clause — it states that qualification decisions are made at the company’s and its third-party investors’ “sole discretion” and are “final and binding,” and contains no fee, no cancellation right and no purchase terms.
Which Mark Spain markets the Guaranteed Offer actually operates in. “Within our service areas” is used as an eligibility rule and is never mapped.
Whether a Mark Spain offer can be reduced after the walkthrough. Their current pages are silent. A 2020 page on their site says the initial offer “is subject to change based on the inspection completed of your home”; nothing published since either confirms or retires that. No diligence-window length appears anywhere.
How long a Mark Spain offer actually takes. Their own pages give at least five different answers, from “within 24 hours” to “typically within five business days,” alongside a five-to-seven-day period for marketing the property to the buyer network. Those cannot all describe the same process.
Whether you can cancel after signing. Their FAQ asks the question and answers it “this will depend on the contract and offer the homeowner has accepted.” The pre-signature promise — no obligation, back out any time — is stated everywhere and is a different thing.
Mark Spain broker licence numbers for four of their five states. The Texas form they host themselves names the sponsoring broker and licence number; Georgia, Florida, North Carolina and Tennessee are not published on the site.
Opendoor’s service fee as a percentage. It does not publish one — the help center says so explicitly. Any “Opendoor charges 5%” you read elsewhere is not coming from Opendoor.
Opendoor’s price limits and exact home-age cutoff. No minimum or maximum is published; age is described only as varying by market.
How much of the resale profit “Cash Now, More Later” actually returns. Opendoor says 100% of profits after fees and costs, publishes an illustrative example it labels simplified, and does not publish the formula, the renovation-cost threshold, or how long the second payment takes.
Opendoor’s true market count. Its help center claims every postal code in the lower 48; its own home sale calculator page and its own Orchard comparison page both still say “50+ markets.” We are not choosing between two of a company’s own claims on its behalf.

The two we would ask about first, if it were our house: the terms the asterisk points to and what happens if you want out after signing. Both are answerable in one email, and neither answer is on either website.

Common questions

Choosing between the two models.

Is Mark Spain an iBuyer?

No, and this is the difference the comparison turns on. Mark Spain Real Estate is a licensed brokerage — its own page states that “Mark Spain Real Estate is not buying your home,” and that the agent takes the property to “our network of pre-market buyers” and brings back competing offers. Opendoor is an iBuyer: it buys the house itself with its own money. So one of them is representing you in a negotiation and one of them is on the other side of it.

Does Mark Spain buy your house?

No. A third party from their buyer network does — local investors, institutional buyers, or what they describe as “home partner” arrangements. Their own page names one of those buyers: “We have strong relationships with buyers like Opendoor because of the volume of properties we bring them.” Which means the two options in your search are not necessarily alternatives. It is possible to go through Mark Spain and end up selling to Opendoor.

How much does Mark Spain charge?

They do not publish a figure. What they publish is that “there are no program fees to participate in the Guaranteed Offer; however, certain buyers in our network may charge fees” — the fees are acknowledged and never quantified — and no commission percentage appears anywhere on their site for either program. If you see a Mark Spain percentage on a comparison page, ask where it came from, because it did not come from Mark Spain. Get their number in writing before you decide anything, and hold Zoom Casa to exactly the same standard.

Who pays more, Mark Spain or Opendoor?

The answer is specific to your address. Neither company publishes a fee percentage, both price per property, and one of them is a brokerage rather than the buyer. Mark Spain does publish a range for its own program — “75% to 100% of market value” — which is their claim rather than a verified figure, and Opendoor publishes no equivalent number at all. The only honest comparison is the one run on your actual address with each company’s real number in writing.

Does the offer change after the inspection?

For Opendoor, yes, and they say so: the final offer follows a home assessment and “can go up or down.” Repair costs come off as a condition adjustment, which Opendoor states plainly are its own internal estimates rather than contractor quotes. For Mark Spain we could not establish an answer — their current pages do not address it, and a 2020 page on their own site says the initial offer “is subject to change based on the inspection completed of your home.” We have not found anything published since that confirms or retires it, which is why it is in the list of things we could not confirm rather than in the comparison.

Is Mark Spain available where I live?

They publish offices in five states — Georgia, Tennessee, North Carolina, Florida and Texas. What they do not publish is which of those markets the Guaranteed Offer itself covers; the eligibility rule says only “within our service areas.” Opendoor claims every postal code in the lower 48 states where single-family homes are available, though two of its own pages still say “50+ markets.” Ask both directly rather than reading it off anyone’s map, including ours.

Why does Zoom Casa have a page about these two?

We compete with both, and every claim above links straight to the company’s own published page it came from, with the date we checked it, so you can verify any line in a click. Where a company does not publish something, we say they do not publish it rather than filling the gap with a number that sounds authoritative — and the list of those gaps is longer than the comparison, which tells you something on its own.

Mark Spain Real Estate and Opendoor are independent companies, are not affiliated with Zoom Casa, and do not endorse it. Their names and trademarks belong to them and are used here only to identify and compare the services. Company statements are quoted from their own public pages as of September 9, 2026. Net-sheet previews are illustrative; final offer terms are issued in writing on a term sheet. Program availability varies by state. Past results don't guarantee future outcomes — not all properties qualify. Up to 85% up front, less reserves. The remaining balance (minus a one-time program fee) is paid when the home resells on the open market. Final terms are issued in writing — not all properties qualify.

Mark Spain vs Opendoor — only one of them is buying your house.