Good advice. I have a friend who is trying to get a well dug and it is becoming very expensive - almost $30k. If he had known it was going to be that expensive, he might have hired a geologist or hydrologist to help place the well to improve his chances.
My advice - don't ask the well driller to help you site your well. Their motivation is to pick a place that is easy to get to with the drilling rig rather than the one that is best for you. They also don't mind drilling a lot of holes if the first one comes up dry.