I got mine changed for about £120 I think, Although i only had one part changed....now my thrust bearing is nackered!!! When I was looking around I recieved quotes from £120 - about £200 that's in Kent.
I've seen cluth kits go around ebay for from £30-£50, although no guarantee on how long one of these will last. Changing a clutch is easy!!! Getting to it is the pain!!!
Correct me anyone if I'm wrong, but I believe you have to remove the drive shafts from the gearbox, then remove the gearbox (remembering to emtpy the gearbox ist), then change the clutch, either 1 or 3 bits of it, then re-assemble in reverse order. A real challenge if ur new to the mechanics world!!