With the proliferation of US and other international commercial companies moving there to manufacture, there is a good possibility that the products are contracted or subcontracted and available thru normal channels, and are perfectly good.
However, with the ebay stuff it is probably a toss-up as to the quality. My daughter and her family live in China. I showed her the link to the eBay stuff last go-round, she says one might worry about the stuff being "out the back door" - something quite common there, in person or over the internet.