That's part of the problem. The game publisher gets like $30 of that first sale, which for some game represents 10 users when you include the people who buy it used. So the people that fund the game get ~$30 for the game and Gamestop makes $100+. At some point gamestop needs to fund games to keep their business model afloat.
It's better for the publisher to make an online game that can't be resold.
I was actually thinking digital sales, like steam and the xbox online store etc. This is a good model. It feels like a healthy ecosystem. Released games are at the $60-70 price-point, which decreased as they gradually migrate into the long-tail of sales.
Gamestop lucked out this console generation when Microsoft caved. I sincerely believe they won't be so lucky next gen.
It's better for the publisher to make an online game that can't be resold.