Even a garage wont charge massive amounts to swap a whole engine, having it rebuilt however does cost a hell of a lot, most garages will sent it on to an engine company. A rough price, for my 16v full overhall (new con rod bearings, piston rings, valve stem etc.. ) was the best part of £800. I doubt it would cost you that much, you would need the crank re ground, bottom end bearing shells, new con rods. Really just isnt worth it. I presume the bottom end gave in without warning too? which would make me wonder if there was another problem within the engine that caused that in the first place....
If you feel up to doing it your self, including cambelt, clutch and full service i put a 2E 8v engine into my gti for just under £220.00