Big varmint,
I have found that coons will generally do one of 2 things when calling for them. They will either climb a tree to see what the ruckus is all about. Or they will charge the call. Usually males will do this. It's a territory thing. When they go into there mating season, the boars can get quite PO'd at the sounds of other coons fighting in their areas. I would say that 80% of the time, I find them looking in the trees looking at the direction of the call. However, when you do get one to charge, it's quite an adreneline pumper.
As far as the fur prices goes, I'm not in that market. I hunt the coons then give them (fur still on the carcass) to a friend that sells them to fur buyers. I'm in it for the population control, helping the turkey pops, and doing skulls for those that want them.