How much do you think I'd get at GameStop for a DSi?

The first edition DSi, not the XL. It's in really good condition, as I hardly use it. I also have Pokemon Heart Gold and Yoshi's Island DS. So how much do you think I'd get for all that store credit? I'm on a mission to get Black Ops. :P

Don't sell to those low price paying swines. It's better to sell it online at Amazon, eBay, or Craigslist.

I answer with another question: How many of us do you think will tell you to call up and ask?

You're better off inquiring your local GameStop about this instead of asking here. It's your best bet if you want a clear answer.