I managed to get a near new set of internals off FleaBay last year, for a very reasonable amount. Keep an eye on the US site and something might turn up whilst saving up for a new set from RGM.
I really want to buy as little as possible from the US, thanks to the customs fees and taxes they lay on you over here. Yes there's often good prices but in the end your'e screwed anyway. So I'm trying to find what I need here in the EU instead.