I don't entirely understand #1.  In your original post, you told us that the seller sold the truck to someone else (or did I mis-read that?).  In any event, option #3 is really:  EITHER forget about the money or sue the dealer.  Unfortunately, it appears that the most you can sue for in small claims court in SC is $7,500, so you'd have to make a choice either to sue in regular court or to sue in small claims court and waive anything in excess of $7,500.