I'm more about quantity over quality, so this may not appeal to anyone but me. First, I'd try to finish off all of my current sets (outside of 2011-12 Past & Present base and the Breakout sets) through Marketplace or COMC (or a combination). Once that's taken care of, then I'd try and buy in bulk as many Pistons cards I could that I don't have, starting with the cheapest. I figure, with $450, I could probably get 200+ Pistons needs after finishing off my sets (374 set needs, though some are Rose RC).
3,850+ diff Pistons cards