I snagged a commercial gas tank on eBay the other day. I went straight to PayPal and paid the price plus shipping. I just got an email saying I got a refund from PayPal. I figured, oh crap. He sold it to someone else or something. I read the message, which said he was sorry, the UPS calculator was wrong. it cost 6 bucks less than the calculator said it would to ship the tank, so he was giving me 6 bucks back. I've never seen that before.