There's nothing to go figure, it's been going on for years. And it's hardly just knives either.
My policy for knives is to study and learn as much as possible about what you want, to the point that anything
out of the ordinary might come to your attention. Don't hesitate to contact the manufacturers' customer service
for help, I have several times. Never buy an existing model on Ebay, nothing being shipping from China, nothing
ridiculously underpriced, items with stock photos only.
As others said, buy from reputable authorized dealers. Read the manufacturers' website they
often have info on counterfeits and identifying them. Buy only discontinued or vintage knives on ebay, after studying the
model. The crooks don't bother copying out of production models.
Buying on the exchange is quite safe as everybody both sellers and buyers here are pretty knowlegable and sensitive to such things.