How to Pay for a Wristwatch?

A few weeks ago, i posted a watch on kajiji for about 500 blocks. A couple hours after posting, i get this response from someone named mike. I agree on the price of the item and the current condition,. am willing to offer you 700 dollars for the payment and 75 dollars for shipping. Well, this guy really wants his watch. So i quickly email him back with my pay pal emal address, thinking i have scored big. The problem is, though, all this was happening on my phone while i was at my son's socka practice, so i wasn't paying a hundred percent attention. Meanwhile, the guy keeps assuring me i'll get the money