One person might mean a demo that proves the main screen and one happy path. Another might include real user accounts, existing-data migration, error handling, tests, deployment, and handover. Those are different pieces of work.
Compare what you will get
Before comparing totals, ask each person what will exist at the end. Is it something to review internally, a pilot for a small group, or a release that real users can depend on?
Then ask what each estimate includes for:
ā¢ Business rules and cases outside the happy path.
ā¢ Existing data and other software the product needs to connect to.
ā¢ Testing, security, and user permissions.
ā¢ Deployment, backups, monitoring, and recovery.
ā¢ Documentation and support after release.
Some items may not belong in the first stage. That is fine if they are named, priced later, or deliberately left out.
Ask what the estimate assumes
The one-week estimate may assume the requirements are settled and the data is ready. The one-month estimate may include time to find missing rules or work around an old system. Ask what each developer assumed and what would change the price.
You can also split the work. Test the riskiest part, then use what you learn to estimate the next stage. That will not answer every question, but it gives you more to compare than the number at the bottom of a quote.