jackson,
There is a good market in ATL for pressure washing.I know several guys that run successfull businesses in and around that area.Pricing varies from location to location so I can't give you anything firm.
There are several BBS dedicated to pressure washing.Just do a google search for pressure washing BBS and you can locate them.Each BBS has a search function,use it.Hidden in the old threads/posts is enough info to answer just about any question you have.