derFunkenstein

Same for me. Sold a 5200 multicart that was working perfectly the day I listed it for auction. Buyer then claimed that the multicart wouldn't boot. I asked him to validate the files on the SD card. He said "I don't have a computer." I asked how he planned on adding ROMs to the SD card if he didn't have a computer. He sent it back and I validated that all the files required were on the SD card. Wound up putting it up for auction again.

That's a bummer. Someone had a case of buyer's remorse in both cases, no doubt. 

I had the opposite recently.  2 different purchases, both arrived with issues because of crappy packaging.  Offered to work with the seller to refund a small percentage, but they refused, so I used the return option.  In both cases, they tried to argue to ebay that it was "buyer's remorse."   I had to provide photos and a video (for a console) as proof.

Oddly, though, when they relisted the items, both were very clear in pointing out the defects up front, and both "buy now" prices were less than what they would have gotten had they simply worked with me to refund a percentage.