Quoted from Chrizg:If you need an excuse as a seller to not take a game back then yes it does hurt the value (Your situation) For the most part, I do not see them decreasing the value as they are another level of protection for the game.
I agree. If he's willing to take the game back at all, it doesn't sound like he's a completely bad guy.
The question you have to ask is if it's worth returning for the devalued price + shipping. Sucks - but it's always part of the risk for buying without seeing it in person.