It's about time. How long does it take to ascertain someone's level of knowledge, the specific aspects of the problem they need solved, etc. What if their app

It's about time. How long does it take to ascertain someone's level of knowledge, the specific aspects of the problem they need solved, etc. What if their approach seems fundamentally flawed, and while it could be jury-rigged, they'd really be better off coming at it from a different angle? How many hours are they willing to be billed for?