>>1917919You can buy fake ones that aren't very good quality. If they're suspiciously cheap that's probably what you're getting. There's lots of fake chinese stuff on ebay and I would be wary of those specifically.
An anon here bought these ones and was saying how poor the quality is, sloppy pivots, etc. Not that you should expect much better for $15.
Anything under $60 is likely to be fake. Whether there are tiers of fake ones and some are quite good I don't know.