The point that the portfolios did not decide it is the most honest part. After fifteen interviews everyone looked capable, and the difference only showed when vendors worked on the client's actual problem.

"Decide what you are buying first" deserves more attention than it gets. A fixed scope project, a dedicated team and staff augmentation fail in different ways, and a shortlist built for one rarely fits the others.

Asking every vendor to write down what the quote assumes is the test I would put first. Two similar prices can describe very different projects, and the written assumptions are the only fair way to compare them. They also become the reference point when something changes later.

At Ascendra Ventures we put those assumptions and the acceptance checks into the fixed price itself, so the client can see exactly what one defined outcome includes. In the fifteen interview case, did the vendor that won also have the most detailed assumptions?