eBay scammers try to scam security expert

If Bruce Schneier can't sell a PC on eBay without scammers trying to get one over him, what chance do the rest of us have?

I expected selling my computer on eBay to be easy.

Attempt 1: I listed it. Within hours, someone bought it -- from a hacked account, as eBay notified me, cancelling the sale.

Attempt 2: I listed it again. Within hours, someone bought it, and asked me to send it to her via FedEx overnight. The buyer sent payment via PayPal immediately, and then -- near as I could tell -- immediately opened a dispute with PayPal so that the funds were put on hold. And then she sent me an e-mail saying "I paid you, now send me the computer." But PayPal was faster than she expected, I think. At the same time, I received an e-mail from PayPal saying that I might have received a payment that the account holder did not authorize, and that I shouldn't ship the item until the investigation is complete.

Given this sort of mess, I really can't see how anyone has any confidence selling (or, I guess, buying) any high-value item on eBay.