Since this issue is big right now, I’ll just weigh in.
Forget about money for a second and focus on the physical reality.
Used game trading is a massively negative-sum economic activity. All those trading shops have to be built and staffed. People have to travel there and back. People have to spend mental effort to hunt around for games at low prices in an opaque market.
Simply transmitting all the games over the Internet, with a universal and transparent pricing model, would be massively less costly in real wealth, physical resources and human time.
Second, note how much used games twist design goals. I don’t like having to muck around with my design to make it monetizable, or freemium, or to make it into a long grind so people won’t trade it in.
Freely-traded used games mean that long-grind games like WoW bring 100% of the profits to the developer (since there is no trading), while short-but-awesome games like Portal and BioShock bring only a small fraction of the profits to the developer (since huge numbers of copies will be traded around, suppressing demand for the new copies). The end result is huge economic pressure away from short, rich games towards all this other stuff.
I’d rather the only pressures game designers were worried about was making a better game. Because this economic twisting effect is seriously affecting how we design our games, and not in a good way. I want more short, rich games.
We Already Live Without It
Funny thing is, we’ve had a trade-less online distribution system for years. It’s called Steam, and it works very well.
And Steam sales demonstrate quite clearly how low new (though not just-released) game prices can go in a transparent market that’s not being flooded by dirty dusty scratched copies of games from a store on the corner.
There’s no reason to make a console phone home every 24 hours, like the Xbox One does. But I really do wish game trading would go away. I think we’d all benefit in the end.