So, I'm going in on an iPad 2 16gb black. I've been communicating with a buyer via craigslist whose willing to sell his launch-day, used iPad 2 for $450 with a smart cover (green, not my favorite color but I'll take it for the price). He says he threw away the box that had the shipping label on it, but he does have the invoice from his online purchase. Is there anything I should be watching out for otherwise? I'll be meeting with him tomorrow to buy it... but seeing an iPad 2 going for UNDER retail just seems fishy in this market.... or am I being paranoid?