Should I trade my iPhone for a Macbook Pro?

To be clear, the iPhone is 32GB, 4S and is unlocked. It has 2 nice cases and 3 chargers, and I put an ad on Craigslist. Someone replied asking me if I would trade them for their 2007 Macbook Pro w/ a cover case, a carrying case, and a remote. They sent me a few pictures of it, and it looks really cool and like a great deal. However, I did a little research on it and it says that the Macbook Pro 2007 version is anywhere from $500-$900. I'm questioning whether or not this is a scam, or just too good to be true. He did provide pictures, and we both clarified what we had so that part is clear. I just don't know if I should go through with it since it seems too good to be true. However, I wouldn't want to pass up on a great oppurtunity like this. Should I trade them across? Also, should I make a contract/bill of sale? Also, where and how do I get one. Please provide full details.

Meeting face to face is important to avoid a big scam, if paranoid you might get a friend to shoot their photo and get a license number in case it turned out to be stolen, a 7 year old computer is pretty ancient, OK if you don't need huge processing power.