Request that the seller let you buy it through an E-Escrow. There is usually a fee (around $20) to use the escrow service, but it is worth it.
You win the auction. You send your payment to the Escrow service, along with correspondence from the seller specifically telling you what you are buying, and your correspondence of what you are expecting to receive. After your funds have been verified, they notify the seller to ship the item. When you receive the item, you inspect it and either accept delivery or NOT accept delivery (I think there is a short time period where you can get it inspected if something needs to be verified as to authenticity). After you accept the merchandise, they send the payment to the seller. If you do not accept the merchandise, then you will need to specify what is not kosher. The end.
As always, check with the escrow service's FAQ to see if their services meet your needs (as to time for inspections, etc.). I believe Ebay links directly to an escrow service but there are actually several out there.
If they buyer is legit, he will have no issue with your use of an escrow service, especially if you ante up for the fee.
** Oh, as far as Ebay's buyer protection: if you pay via Paypal using a credit card, then you have some recourse to get your money back, but it is an very gray area. All Ebay will actually DO if you are screwed and can verify it is "take action" against the seller. "Action" is anything from an email "warning" to the seller all the way up to freezing his account and feedback and forcing him to sign on again fresh and with no feedback. None of these actions does much to help the screwed buyer.