I play on PC. My brother wants to start playing, and will be on 360 since he doesn't have his own PC. The Ultimate Collection that includes all xpacks is way too expensive on 360 (like $90). The old version w/o Aby xpacks is only $10 for 360. If we just buy that and install the game on 360, could we then get the Ultimate Collection for PC (for $10), register those xpacks to his character using my PC, then have him switch back over to 360? I'm not sure if it works that way or not. Advise, please?