Relatively speaking, it is the same exact thing. To a 13 year old, buying a video game is just like a 30 year old buying a car. Relatively, to a 13 year old, that video game has just as much value as a car does to a 30 year old.
It doesn't matter that the car costs 500-1000 times more than the game, the principal behind it is the same.
Regarding your comment on the financing, there are people out there that do consider financing video games in bulk, maybe included in a package deal with a TV or something, but the games are still included in that financing. Not probably, but still possible.
On the other hand, publishers could argue that the code on the physical media is licensed and not owned by the consumer. But the way around it, I think, is for consumers and Gamestop to say they are selling/buying the physical media and not the code on it. Who knows, its just the publishers trying to squeeze every penny out even if it isn't possible just like the publishers in the RIAA have been doing for the last decade.