Well to be honest, I think its kinda dumb that gamers whine over a game being opened. Does that game being opened all of a sudden make it not play as well? No, its the same f'ing game. The code thats imprinted on the disc is the same, it hasn't diminished in any way shape or form. You aren't buying a car, there is no "mileage" to a video game.
But, on the other hand, its an opened product, Gamestop wont return it as thus, so why should the consumer pay the same price as a sealed game. I mean if you go to Best Buy or Target and they have to open a TV to place out for display, even if that TV isn't ever turned on, by the virtue of it being opened, gives the consumer a discount. Not sure why GS doesnt do that. Id have to guess its because they already make such pitiful profits on a new game sale they don't want to have that slashed.
So i see both sides. Gamers whine because, well thats what they do and Gamestop clinches its fist around its money, because well thats what they do. Its a headache being caught between the two.