Im getting the PS4 around Christmas (or whenever it drops) and Im definitely getting Ghosts for my PS4. Now, I really want to play Ghosts on the release date, so I'm buying it for ps3 as well. I know this is a waste of money, but hear me out. Trade in your copy of COD: Ghosts about a week before Christmas, and you will probably get around 50 dollars back. 15 dollars to play the game early seems like a cool deal to me. Just thought I'd share a way to save money if you want to play Ghosts as soon as possible!
You will probably only get about $35 dollars back from Ghosts.
You'll have a better chance on craigslist or eBay.
(Now how to take the sting out of the PS4 retail price, that would be the real trick).
It's still possible that Sony might restrict used games, so that $50 you were counting on might be a lot less.
Also, I doubt any stats will carry over. I think your idea is a bad one.