Without a picture a detailed description is in order. I looked up the auction in question.

It would seem to me that the starting bid and buy it now prices that you set may have led the buyer to believe the items to be in better condition than they were - relative to starting prices for similar items with photos and detailed descriptions. Perhaps the buyer should have asked questions but he didn't.

If the items had damage or noticable wear and tear on them a copy of a detailed listing of these should have been included in the package. This would clear up any disputes as to damage in shipping.

The buyer has a hundred percent rating on 68 transactions vs your 100% rating on 14 transactions. Make of that what you will.

You can give him a poor rating and you can attach a rebuttal to his rating of you. That's about all you can do unless you can come to a compromise that will give positive ratings for both you and the seller.

If you do give him back some of his money both of you need to inform eBay as they base their cut on the ending price.