I've personally bought at least 10 of these things. Some of us build keyboards for fun!

Really? Why?

I know people who made like 3 or 4 of these keyboards from kits.

That I think they are insane and just buy the chinese knockoffs does not negate the existence of the other guy.

If you find that hard to believe, keep in mind this is just one product in a rather crowded niche marketplace, so there's undoubtedly tens of thousands more similar products that have already been sold.