Prices are different all over so thats a hard one to answer without knowing where youre at. Also, connections play a role as well. As a beginner youll likely pay top dollar in your area, especially if you appear to be unknowledgeable.

Check here for some base info to answer some of your other questions. Its a reliable source of facts that I highly recommend.
http://www.erowid.org/plants/cannabis/cannabis.shtml