Scope sets the cost of an MVP, so a number quoted before anyone understands what you are building is a guess. A few decisions drive a large part of that cost, and you can check each one against your own plan.
- How many separate interfaces does it have?
- A customer app, an admin area, and a staff app are close to three products sharing one backend.
- Does money move through it?
- Taking a card payment is well-trodden work. Holding funds for other people, as a marketplace does, is a different category of software.
- Which outside systems does it depend on?
- Each one is another company's API, with its own failures and release schedule.
- Web only, or native iOS and Android too?
- Each native app is another codebase, plus its own trip through store review.
- Does it handle legal, health, or financial data?
- If so, the controls are engineering work inside the build, and they can be planned for from the first release.
- Does the AI call an existing model, or does it need one trained for your domain?
- The first is inexpensive to build on, and the second is a different budget.