Not eBay themselves, but I was looking at secondhand dresses on eBay. Found one by a British designer. The dress is worn and has some marks and fading. And is overpriced imho. The (delusional?) seller is stating "positive feedback over 300 required". Looking at their other listings, they make differing positive feedback requirements for everything they're selling.
Is this a new thing, or even allowed? They're unlikely to sell much with such arbitrary requirements.