The easiest way to know if if’s a clone is to try and find a clone. If you can, just buy from an AD. Benchmade, Kershaw/ZT, and Spyderco have just about all their popular models bootlegged.
That’s the “shaky videotaped from the movie theater” copy of that knife.
AliExpress has some fake knives that are good quality for their price (notable Jufules), and some that are of very poor quality even for their price. I’d imagine most eBay fakes will fit into the latter category. Personally I have a Launch 9 clone I got for $20 with good action that cuts pretty well though the steel seems pretty cheap, and a beautiful titanium scale Paramilitary 2 clone for$50 that I carry most days for cutting boxes. You can find discussion of some of these on old.reddit.com/r/ChineseKnives