Best of luck hydorah - I've actually been quite surprised by eBay finding in my favour when I've had to deal with idiots.
My favourite was when I sold an old Apple laptop. It went for a surprisingly high amount, I posted it out by Special Delivery, the buyer left me feedback a couple of days later saying it was excellent and everything was perfect with the transaction. She then contacted me two weeks later through eBay along the lines of "I have since tried to sell the laptop on and have found out that it's not really worth what I paid for it. I want to send it back and have a refund. If you don't agree to this I'll tell eBay that it didn't arrive and you'll have to refund me anyway."
When I sent a short, but polite, answer telling her that a) she'd already left positive feedback so that might be difficult, b) Special Delivery is insured and traceable and recognised by eBay, and c) the whole point of eBay is people pay what they think the item is worth, I didn't hear from her again...
: P