John, I replaced one for a friend of a friend. Usually what wears out is the clutch disk while the flywheel and pressure plate are in good enough condition that they can be reused without machining. If you only need the clutch disk, rebuilt ones cost about $55. If the pressure plate is seriously grooved, a remanufactured one is about $85 (prices from CT Farm - others could be lower or higher). You can't really resurface a pressure plate because the dimensions will be wrong and will limit the life of a new clutch disk. If the flywheel is damaged, a good machine shop should be able to clean it up for $50. Throw out bearings are about $15 to $20 and pilot bearings are usually less than $10. Doing the job yourself could be as cheap as buying a clutch plate - $55. If you have someone do it for you, they will recommend a new pressure plate, pilot bearing and throughout bearing as well and some will want to machine or replace the flywheel. With labor it will probably cost $350 to $500 or even more. The guy I did it for paid me $100 and needed $80 in parts. The job took about 3 hours (two weeks elapsed time because he didn't have parts in advance). His professional installations estimates started at $500. I think we did this three years ago.
Good luck. Email if you want to ask other questions.