You send one brief to three suppliers and one quote comes back several times the size of another. The reflex is to assume someone is padding. Usually nobody is: the quotes are answering different questions, because the brief let them.
What you are actually buying
A custom software estimate rarely covers only writing the code. The same number quietly absorbs work the buyer never sees in a demo and the supplier does not always itemise.
- Discovery: who decides what the product does, and how long that takes before a line is written
- Interface design: whether it is included, or assumed to arrive from your side
- Data migration out of the current system, which is almost never clean
- Integrations with what you already run — invoicing, accounting, CRM, payments
- Testing and post-launch fixes, and for how long
- Hosting, monitoring, and who answers when something breaks at 2am
A quote that does not mention these lines has not removed them from the project. It has moved them outside the price.
Fixed, estimated, and the difference between them
A fixed price on a well-defined scope is honest. A fixed price on a one-page brief means someone has priced the unknown — usually as margin, sometimes by quietly deciding what will not get built. When the scope is not settled yet, paying for discovery on its own costs less than a fixed price built on guesses.
The questions that change the answer
- What assumptions did you make to reach this number?
- What is excluded that might turn out to be needed?
- Who owns the code, and where does it live?
- What happens to the project if the person who built it leaves?
- Can you show me something working of comparable complexity, not a mockup?
That last question separates suppliers faster than any price negotiation.
