About a week and a half ago,I sold a Gucci Sukey bag.I bought it from Gucci.com.I haven't ever sold much on Ebay or something that expensive,and I was nervous,but I haven't ever used the bag so I decided to chance it.Today I get an email from the buyer saying that he thinks it's a fake.I don't have a clue what to do now.I state "no refunds"on my auctions,but I'm afraid the guy will switch the bag with a replica and stick me with it.The bag is totally authentic,but the guy is saying he needs proof.What should I do?This is making me a nervous wreck.Thanks for any advice!