GameStop retail locations offer a $75 credit toward a new PlayStation 4 Console when you trade in a PlayStation 3 80GB or Xbox 360 (4GB or original). Alternatively, get a $150 credit when you trade in a PlayStation 3 120GB or higher or Xbox 360 250GB or higher. It's the second best trade-in credit we've seen toward the PS4 at GameStop. (It offered a $100 credit for the lesser systems in June.) Deal ends September 14.