I once bought a fancy”Audioquest” hdmi cable on eBay at about 10% of retail as an experiment. Was it fake? You bet! Did it work? Yes, but a real Audioquest cable that I had (a supposedly cheaper model) had much more vivid picture.
ebay has turned into a cesspool. 15 years ago it was an exciting place to buy stuff (I got a great deal on a very nice Stellarvue app refractor, you can’t fake Starlight instruments focused!).
Don't buy from China or Hong Kong on EBay, is my advice.