> So I go online to leave a review and warn people off... only to find that the seller "no longer existed". They absolutely did, and were selling their awful snips but had changed their name and paid for a bunch of 5 star reviews again.
I wouldn't be so certain about that. I've found that there are a lot of sellers selling the same things, but they're not the same sellers under different names, they're just getting stuff from the same places. Often, for cheap things, the source is AliExpress (or Alibaba), or potentially cutting out that middleman and just getting them direct from the companies that sell on aliexpress/alibaba.
It's also been my experience that pretty much _anything_ that isn't a big name brand item being sold on Amazon can be found for much much cheaper on Aliexpress. The exact same product, just without the 1000%-2000% markup.