I doubt if anyone can quote you a price over the net, even at plbg.com where they dodge the pricing issues. Besides they would want to know if you want cheap, average, or expensive faucets and fixtures(k-mart, delta, or hans grohe brands). What type of pipe do you have and how much and how far do you want it replaced and with what kind of new pipe? Is it totally accessible or do they have to chase through walls and ceilings to get to the piping. Is your piping so bad that if they touch one part they will have to replace more than you planned on? What kind of wall and ceiling material has to be torn up and replaced and how much material. Is the shower wall tile or a surround that has to torn up to replace the fixtures and if so would the entire shower wall and floor and shower pan have to be re done or retiled or resurrounded? Are similar materials available to determine whether the walls and ceilings can be matched or the entire bathroom redone new? Can you post a picture somewhere? Just some of the questions someone would want to know to even come close to a ballpark price.
Find some plumbers who specialize in such repairs and some who will bid the job in. They should be out there. I doubt they are interested in telling a diyer how to do his job for free though. Many plumbers just like to do new construction work or just work on the piping and let a carpenter or tiler do the rest of the construction work. Some may be so busy that they don't need the work and the chargeable visit is to separate the wheat from the chaff so you may want to avoid them anyway. You may need two bidders for the job, a plumber and a contractor. Some remodeling contractors take care of the plumbing/plumber as part of their bid/work.