I've been nabbing up some new sealed games from ebay, so when I receive the games, I immediately take the shrinkwrap off, test/play the game and then place the box in one of those videogame protectors.
It's difficult to find boxes in good shape, there is always some issue, I felt it was the seal itself, is this really the case?
Did Atari put them on too tight or something? Is it because of age, the cardboard used?
Actually the only mint boxes for the 7800 I found were the big ones from Absolute Entertainment.
In comparison, new, sealed 5200 games, the boxes look/are mint, could be because of the different type of boxes used.
You can tell Atari spent more money during the 5200 era (boxes, nice formatting description, color, etc) vs. the 7800.