Not OP, but when I did my startup I also tried coaches, and the first one I talked to was kinda like what gold diggers would be in a relationship context (asking high price, since he knew we raised, and in the demo sessions provided superficial value), then I finally went with one who actually had business experience and uni degree in psychology and provided modest but solid advice for a fair price, that was quite helpful in those difficult times.

So I guess spot and avoid sweet talking charlatans (this applies to all business relationships though).