The mega-mart for all things gaming, GameStop, would love to buy any and all games and accessories that you have on hand. All of it at the lowest purchase price to turn it around and mark it up enough to create a nice, profitable margin.
If you're not trying to sell them back a PSPgo, that is. The following screen cap (from Cheap Ass Gamer) shows a clear disdain for the system as it is excluded from a recent promotional ad GameStop ran:
Now, don't panic. If you made the bold decision to buy a PSPgo last year and were thinking of trading it in, the ad doesn't say you can't trade it in. Just that, you know, GameStop doesn't want it enough to give you extra cash money for it.