I'm a firm believer in Chinese products - the majority of the rather nice 'special' mics are made there, or at least have been assembled from their parts that I am happy with their stuff and a few years back I bought some that were cardioid and omni switchable, and they've proven a great buy. This kind of thing
Best quality cardioid/Bi/Omni wide application wired electret condenser studio Karaoke recording microphone YR01|recording microphone|quality microphonemicrophone best - AliExpress
You need to remember that these things are to all intents and purposes one-offs, assembled by small office/workshop tiny businesses in big co-op communities. So they'll have an idea, buy the PCBs from somebody else in the building, put them in a housing from another, using elements from another. They'll know nothing about them apart from what they look like. Buying two will give you a stereo pair. Buying one, liking it and ordering another could give you something sounding totally different - so there are risks. I have had hundreds over the years, and kept lots for my own use and sold the rest. Only two have been terrible. most are perfectly usable and sometimes there are just gems, and I guard these carefully. The one in this ad is very typical. The body is very, very common - lots of mics available use exactly the same one. I think the pub is familiar, but of course by the time they arrive it could use a different one.
My advice would be to buy two of these, or do some time consuming hunting - keeping in mind that searching for omni rarely brings back omni mics - lots are described as omni when clearly they are not!
Get them, try them and then either sell them on ebay and recover what you paid, or use them.
I firmly believe that lots of the boutique mics people rant about are actually just lucky combinations of parts that play nicely, and not some kind of really clever design or production care.
I've bought so much from China in the last few years I've got friendly with many of the suppliers and they quite happily reveal how they produce things. I think I have said it before, but I sent one of these suppliers a picture of an old German stereo large diaphragm mic and asked if they had anything like that. Two weeks later they said they could do it. I needed to commit to buying 5 because they had to source the parts. I got a stereo omni/fig-8/cardioid mic, beautifully built by hand that works like a dream. Sold the other 4 to enthusiasts going me mine for free!
Don't be afraid to try things - good fun, actually. The firm I bought my microphones from still exist, but they make stage lighting now, not microphones!
Lots of so called manufacturers now buy in Chinese mics, polish the cases and rebox them. A good product still - so what?