If they don't transfer, but instead you buy the game, that's how they would keep up business, a one-time purchase, for example. Then, you can go in-game and customize, or perhaps a point-system can be integrated, much like Halo: Reach, with a few differences. For example: If you are on a winning team in a team game, then you get a point, certain amounts of points could then be used to buy skins and voice packs. Thus, you don't actually need to spend more money to get everything back, since from what I've gathered, its more than possible that our IA accounts won't transfer from anywhere. No guarantees on any of this, I'm pretty late on the uptake of these things, but for customization, that is what would make sense to me as an option.