Don't sell anything valuable on eBay. As others have already said, they're a shower of cocks.
I listed my 2009 MacBook. I said I'd only sell to people with good feedback. The winning bidder is someone with zero feedback who has only just opened an account two hours before the auction closed. So, naturally, I refused the transaction.
eBay said that if I cancelled, I'd still need to pay all the fees: between the listing fee and the final value fee, it was £40 (about $60). They were useless on the phone: the guy actually said "I can see you're right, but there's nothing I can do. Just pay the fees and learn from the experience".
I sent them a letter, threatening to take them to court. The fees vanished from my account