We exchanged a few more messages and he accepted that I am going to wait. It turns out he is a kid, 16 years old. He said his mother sent it out and didn't get tracking.
At first he started in on me about "I'm just a kid, and I worked very hard to earn that MMM. I just sent it halfway across the country to some stranger, and how do I know you will send me anything?"
I reminded him I have 37 positive feedback and he has 2, and really it shouldn't be MY integrity being called into question, especially since he was the one who didn't follow the agreement. I also told him if he is 16 and doesn't feel like he can handle the responsibility and risk he shouldn't be making trade deals online.
hell, at 16 I had all ready maxed out the 5k limit on a PP account...
I have done 100s of online trades/purchases, I have only been scamed twice, both of which I went against my better jugment and bought/traded with someone with low/no feedback...