Studios vary greatly in size, scope and equipment. From your passport photo shooters (ok, barely a 'studio') to indoor setups big enough for vehicles. Rental, manpower, equipment, fixed costs, expendables, etc -- a large number of things you need to take into account.
I think you'd get better response posting this in The Photo Biz section where a number of working pros have shared their knowledge and experience (better close this thread first though - not nice to cross-post!)
U wanna do it commercially? Is it to be rented out? or? U didnt specify it. For home use, the investment is lesser and i've helped peeps to kinna set up before. For commercial use, ur clients tent to expect much more.