I once bought a card of 6 lithium batteries from Hong Kong for $1.20 including postage. They arrived after only a week or so.
I remember wondering how in the world they could do that. BTW the batteries were fine.
In the interest of honesty, I admit I’ve bought items off eBay from Chinese sellers too. Some such items cannot even be found, or at least readily from US sources, eBay or not. (I’d guess that either the Chinese sellers “got there first”, or drove out any US competition some time back.)
One still has to survive on the very “unlevel” playing field. In business, one has to find the quality that makes sense for the $$ and the market, or you die. But that doesn’t make the playing field “right”.