What the Hell? or Money?!?!

I have an odd tale to report that's ending is yet to be determined. It all begins with my posting my gamecube for sale on used winnipeg.com, a local classified website. I received an email in broken english from someone proclaiming to be from Dubai wanting to know if I would ship it there. Thinking this was some scam I did not respond, but kept getting the same questions from him. Finally I said I would for and extra $100 on the purchase price. He immediately asked for my address, which I was weary to give, so I gave the one for Greyhound downtown, where I could pick it up. He then said that he would send the money order through "a local courier company" and to please let him know when it arrives.
At this point, I assume the whole thing is still a joke, until yesterday when I found a letter "from Dubai" in my mailbox at work. This letter, while the front is stamped with Dubai postage, contains an interior letter that has a money order drawn from the Bank of America with an address from someone in Louisiana. the money order appears to be legit, but is for "950 dols 00 cts." I have no idea which currency it is in, but I will assume American. If this is legitimate, why did he send me $300 more than I asked? I have a strange feeling that this is not on the level, but have never heard of any kind of scam like this before. Has anyone else? It would be super awesome to have another $1000 on hand, but I am not holding out hope for the smooth working of this transaction.
In other news, I have been working and doing little of note. Well, I guess reading, working out, and watching DVD's is of SOME note, but not much... that is, unless Erin is around.