Neither story really holds water. I don't think it is possible to edit the ad and raise the price, you can only add information not change what is already there. So he couldn't have raised the price on 12-8 as claimed.
The seller has 2 ads for the same item within minutes of each other, the second one having a lower price. Possible mistake, I guess but who knows.
My real question would be how much money was truly sent and what were the conditions. If you give me a deposit and tell me you will have the rest in 2 weeks, then fail to hold up your end of the bargain, you lose plain and simple.