Mate i know exactly how you feel, mine went from a simple coilpack to a rebuild overnight, but im on 70k now with a new rebuild running best its ever run and if i had the money it would be the ideal time for a bigger turbo.
Sorry to hear about it though its such a pain but imo you arent throwing the money away, it'll be worth it and you wont get as much for the parts and then fork out for a new car for what a rebuild will give you.
My car is worth much more to me than i could get for it, plus the fun you'll get from a bt is priceless!