Selling a SaaS template is an odd place to stand while writing about SaaS templates. I am writing it anyway, because the question I get most is an honest one and deserves an honest answer: what exactly am I buying.
The short version is that you buy time in one specific part of the work, and no time at all in the others.
The part you can buy
There is a set of things every SaaS needs and none of them differentiates any SaaS from another. Signup and sessions. Subscriptions, recurring billing, upgrades, cancellation, the webhook that tells you a payment failed. The panel where you change the catalog yourself without opening an editor. A blog with a sitemap, hreflang and structured data. Migrations, pipeline, deploy.
Writing that is not hard. It is long, and every item hides two or three traps you only find by falling into them.
In CastorStack that set is: a .NET API with 32 migrations and 310 tests, three frontends in React and Next.js, two real payment providers behind one interface with country routing you edit from the admin panel, signed webhooks on both sides, a product and plan catalog with multi-currency pricing, feature flags with a kill switch, an audit log, a database-backed blog with the SEO plumbing attached, three languages throughout, and 70 end-to-end tests running in Playwright.
You could write all of it. The question is whether you want to spend the next three months there instead of on the part that is actually yours.
The part that is not for sale
Niche. No code knows who you are selling to.
Distribution. Still the most expensive item in a launch, and it got more expensive the year search started answering questions without sending anyone to your site.
Pricing. How much to charge, how many plans, what goes where. The template sets the table for any configuration, and the configuration stays your problem.
Support. The day a customer writes in to say they were charged twice, you are the one replying.
Be suspicious of any sales page suggesting otherwise. A template solves the cheapest item on the list.
Free boilerplate versus a maintained template
A public repository with the start of a SaaS is useful, and there are plenty. The difference shows up a few months later.
When the payment provider changes its API version, when the framework ships a major release, when someone finds that a default setting left the database exposed, the abandoned repository does not change. You are left with the problem and without the context of whoever wrote it.
What you pay for in a maintained template is continuity: someone follows along, fixes things, and writes the version's migration guide. It is the same reason companies pay for libraries they could have copied.
There is also documentation, which almost never comes along with free code. CastorStack ships fifteen onboarding steps in three languages, architecture specs, guides for the blog and for setting up Paddle, and an environment-variable inventory separating what is public from what is secret. None of it is glamorous. It decides whether you are running in two days or two weeks.
The questions that reveal what it is
If you are evaluating anything in this category, mine or someone else's, ask what it does not do. A specific answer is a good sign. "It does everything" means brochure.
Ask what happens when you want to change database, payment provider or hosting. If the answer involves rewriting half the system, the purchase price is only the deposit.
And ask how many tests there are and whether they run. Tests are the only way to find out that the code does what the sales page claims without reading all of it.
What CastorStack does not do
No organizations, teams or multi-tenancy. No two-factor authentication and no social login. API-key authentication is modeled in the database but not implemented, and the spec says so plainly, precisely so that nobody presents it as ready.
The admin panel reads users and subscriptions, but it does not yet change roles, block accounts or cancel plans on the customer's behalf. There is no webhook dashboard: what happened is in the audit log, and diagnosing means querying that log. There is also no automatic sync with the Stripe or Paddle catalog, so external identifiers are typed by hand and a wrong one only surfaces at checkout.
That list exists because each item is a scope decision, and deferred scope is cheaper than scope done badly. I would rather you read it before buying than find it afterwards.
Why this changed in importance
While writing software was expensive, buying finished code saved money. That is no longer the case: generating code got cheap enough that the saving changed in kind.
What a well-maintained template sells today is not code, it is the list of decisions already made and tested. Which of them you want to make again is the only question left.