Well, what do you expect? Other sellers can get guitars over to Europe for a third of what you quote. Of course people are going to ask you to double check. They think you are trying to screw them out of $200. A simple note in your auction (in a w-a-y more diplomatic tone than you have used here, I would advise) about how you only trust FedEx, and that they cost $300, and perhaps a link to their online quote, would put an end to all this. You could then continue to offer your guitars to everyone and get more bids on them. If you are willing to break your vow, that is.