True, but how can a non-technical founder know who is good, or who is just expensive? I've seen dev consultancies that are very expensive, and they play the part in every way, but they produce total garbage. There really isn't any way to know unless... well you know.

The best way to figure it out is through a vigorous investigation of references I think, but even then, the past projects they worked on may have been better suited to their skills that what you're hiring them for.