My rule of thumb is that I never spend more than $20 on a game, new or used. I hit the clearance end caps at Target at least once a week, so I find a lot of sub-$20 deals on 3-4 month old games there. My gaming backlog his huge anyway (still haven't even touched that $20 Valkyrie Chronicles I bought last year), so I don't care about getting stuff on release day unless it's something I REALLY want.