Are there any sites out there that list the day-to-day trade-in values for old games at places like EB or GameStop? I realize this would be a large undertaking but I think that it would be extremely useful. I want to go get MGS:TS and I have a few old games to trade in but I would like to know how much I could actully get in store credit... Maybe Cheapy D could set something like this up similar to the CAG-o-matic... 