I'd stay away from it. If you already have a Gold membership, I don't think it will work for you anyways. The 48 hour codes come in a lot of games, and I've never heard of anyone selling them. A 3 or 12 month card, yeah, but not a 48 hour code. It's not really worth much of anything. Also if you give him money, and he give you a code, who is to say that the code will even be good? If you don't have Xbox Live Gold and want to try it out, I'd suggest just paying for a month on the marketplace or getting a 3 month card at the store.