The idea of a graphite bow is it is more stable than wood and it can be manufactured with great consistency from one bow to the next. The disdvantage is it isn't wood
All the scuttlebutt I have heard is that pros with graphite bows use them as backups or in situations where they are worred about damaging a really fine wood bow.
The prices vary a lot, the Glasser carbon fiber bows are about $300 and the cheapest I've seen. They are also the most detested. Carbow starts around $600, I think. There's a French brand whose name I don't recall that is more like a grand...you can get a pretty sweet wood bow for that much!
I've been sniffing around the Glasser since I'm ready to move up from fiberglass

and like the low-maintenance aspect of the graphite bow (my first bow 20 years ago actually was wood, but it was also warped; when the local bowmakers told me it wasn't worth fixing I wasn't going to buy a $300 bow to go with my $300 bass

).