I personally have never sold anything on eBay, just bought.
I have been ripped off once, but the cost of the item ($150 USD) wasn't worth the time I would spend on getting the issue resolved. I left the seller a 1 star rating, chalked it up as a lesson learned, and moved on. The seller did get royally upset at me for the 1 star rating, though. So, there was
some amount of satisfaction on my part there. I guess in the end, it was a win-win.
They got my $150, and I made them angry for the justified 1 star rating.
Their venom was a bit over the top, though. The f-bombs and whatnot weren't really justified, IMHO. Some people just don't deal well with stress, I suppose.
On the flip side, I don't think I will ever sell anything on eBay. I have heard too many stories these days about buyers scamming the sellers (reverse scams, I call them.) Can't be safe anywhere online these days, I suppose.
My advice is to use something like Craigslist, and sell it to a person that's local. Meet in a public place (Apple store, for example) and do the transaction there. Cash only, "as-is, all sales final" type thing (but provide full disclosure to the buyer about the system's history ... issues, repairs, etc.)