Of course they sit, they're overpriced. No one is going to pay the ridiculous prices that most used game stores slap on their product. In some cases, prices are higher than Gamestop ($80 for a used PS2? Really???), so no they'll never sell that crap. The fact that they got it for $8 in store credit never crosses their mind that maybe they should just drop the price a bit.
I'm sorry but I have zero sympathy. If you don't have a working model of how you're going to turn a profit at your business, then you should go broke and close, it's as simple as that. And yes, thinking that you can charge double what fair market value is, is not at all a working model. I've seen em try, it doesn't work.
So if they store knows they can't sell the game at the stupid price they're trying to get, wouldn't it make sense to not keep trying to get that stupid price? I can slap a $10 price tag on a loaf of bread and watch it sit and grow mold, but that won't sell the loaf of bread.