eBay is FULL of scammers and people trying to get everything for free.
I recently sold my Retron 5 to a buyer who was initially correct in that I forgot to include the AC adapter in my initial shipment to her (it fell under my car seat on my way to my shipper and I didn't notice it while boxing up the system), she proceeded to plug any AC adapter into it that fit despite my explicit instructions to NOT do so. I sent her the official adapter the next day but the damage was done. She had fried the console by using an adapter that had too much current, and even admitted this to me in writing. That didn't stop her from filing three separate claims with eBay under the pretense that I sent her non-working goods or good not as described. I was appalled that every time eBay ruled in my favor that she was still allowed to open new cases about the same thing over and over again. It took a very angry call to their customer service to finally get her off my back.
What I do with EVERY electronics item I sell on ebay is a shoot a video showing the item, its serial number, and the fact that it powers up, works properly, and has no cosmetic damage. In that video I include the date, time, and the buyer's information. I did NOT do this in the case of the Retron because I was in a hurry and it almost bit me in the ass. This DID save my bacon on two other iPhones I sold on eBay, though.
Make videos, don't let the buyer know they exist, keep them until after eBay's buyer protection windows elapse.