How much will gamestop give me for my old DS games?

The price does vary with the game. Most of the time you won't get a max of MAYBE $10 for each one. I sold mine on a href="http://www.craigslist.org/about/sites" rel="nofollow"http://www.craigslist.org/about/sites/a and got almost as much as I paid for them cause they were in the cases and barely played.