First, they can't take sealed new items (it's a company policy to coincide with many states' laws on pawning goods of non-business licensed individuals). Secondly if he wanted to return it I know Walmart and a few other retailers have a once per year no receipt for store credit policy on items, probably should have done it through them.
Damaged used items are often sent in for refurb and also are typically returned anyway (it's not like they are forcing you to take them). Also your paying for the game, not the case or the booklet, which in most modern games consist of nothing more than 4-6 pages of useless information and legal jargon.
Finally there is no money in new games or consoles. Gamestops profits on new titles is about $5 for 50-60 dollar games and less for cheaper releases. $10 on guides if the...