Ethics is numero uno.

In my humble opinion, based on the facts as presented in your post, you have done everything a responsible seller should do and everything a responsible buyer should expect. If a buyer wants to be sure of satisfaction in a transaction,then he should be willing to insure the delivery. My understanding is that if you pay by Paypal, the buyers purchase is guaranteed, as per a refund from Paypal. I am sure that your rating is 100% and you have never had a problem before. That should mean something to the eBAYers.

Good luck,

Dan