Well, if "they" can get away with sub-par knock offs and downright fakes and neither eBay etc. nor consumers care, then who's stopping them? Also ever wondered how come you can buy things from China with free/very cheap postage to the other side of the world? I have, and found out it's because the post offices in "rich" countries basically transmit those letters (and often 'letters', because in reality they are too big) at their own expense, because China is still considered 'a developing country' or some such in certain international agreements, which means they are still having benefits like that postage thing. The end result is bizarre, I've realized often it is very much cheaper and easier for me to buy certain small/cheap things from China instead of a local retailer or have them shipped from other parts of Finland. Often packages that would cost me about 5 euros within Finland will be free from China. But it is by far the largest manufacturing country in the world, are these weird benefits still really needed? At the same time, China probably has some of the most hightech plants in the world these days and they are capable of excellent quality, so no reason to automatically view "Made in China" as some sort of badge of mediocrity - just don't expect $5 and $50 buy you the same thing because they look similar enough on the surface.
Sorry don't mean to tangent into politics, I'm just saying you should think twice when getting the cheap, clearly counterfeit/copycat stuff from China. A lot of the time you get what you pay for. Also something like a headshell is such an important piece in the chain and lasts basically forever - no reason to skimp on it IMO, especially when you can get good quality new headshells for something like $20-40 and if you spend that amount of money on used and search around, you can get vintage headshells of incredible quality. A $5 headshell might be just enough to get you going with a $10 cartridge, but anything more than and you are likely wasting a good cartridge on a headshell with sub-par materials and tolerances. In my experience with these $5 headshells your chances are about 50/50 to get an acceptable one.
If money really is that tight for this hobby, that $5 vs $40 is a huge thing for a headshell, then even more so I would suggest to make good decisions and invest in quality. Through the years with this hobby, I've realized overtime the money sink is not the good components I bought - those are one time investments and usually hold up for years and years + they are a joy to own and use - but the cheap ones. Instead of a $50 headshell and $150 cartridge you might end up spending the same total on 5 headshells and 5 cheap cartridges - and not be quite satisfied with what you have. This is also a mindset this I think the world in general would be better off for - we are drowning in cheap throw-away junk. I think both people and the environment would be happier for it if we started to only buy things we really need and things that give us pleasure in ownership for more than the very short high of "getting something", which lasts at best for maybe a day.