[LeonTurbo]

Right earlier today my Scooby decided it didn't like the gearbox anymore and while on boost in 3rd gear it popped out and now sounds like its full of nuts and bolts, Car still drives fine in all gears apart from 3rd which has no drive, gearbox is very noisy throughout all gears though. Now am I better off getting my gearbox rebuilt or is it easier for me to source a replacement box and do it myself on the driveway?
Roughly how much am I looking at for a decent recon or low mileage box, my car is a 2.0 turbo facelift classic, the engine is uprated producing 352bhp but was still on the original turbo2000 gearbox that has now had enough. Any advice or help would be greatly appreciated. Leon