You bought them, paid legal tender for a legal transaction, it's yours.
Offer it back at $ 100 rate per your hour spent on shopping, only fair to both sides. Plus like 25 bucks per hour on the car.
If they are serious about the remorse and want the games for keepsake it will be fair deal.
And if that would have happened to me I wouldn't even consider selling back.
If they are only in for the extra $ then forget about it.