First and foremost I am a cart collector, primarily to play the game. Clean pins and a functional game are my absolute priority, with cart and label condition as a secondary aspect. However, I wouldn't buy a game with a totally fucked up label, or with too much rust and dirt all up in there, so it does effect my decisions to an extent. Better condition is always better, but I do have some yellowed and marginally sun faded games in my collection nonetheless.
When it comes to boxes, I'm kinda the same way. Better is better, but I am willing to put up with significant wear on boxes, as long as the overall appeal is good enough. For example, I wouldn't buy a boxed game that was totally faded or destroyed in some way across the front to ruin the box art. But, banged up edges, a little crushing here and there, some tears on the sides, not an issue for me.