I gave Alibaba a try
Figured I should give it a chance. I was looking for a cheap power transformer, the kind you find as part of a small DC power supply, 24 watts or so. In my query, I provided fairly detailed electrical and mechanical specifications.
What I got back was basically junk. Lots of spam from Alibaba itself, spam from freight forwarders, a couple of replies offering power transformers of the kind you find on concrete pads outside manufacturing plants...and one or two legitimate replies.
My conclusion? Far too much filtering required to find anything I need. And the communication barrier, of course. Bare minimum (and sometimes, not even that!) product information. Formulaic responses, repeated verbatim in response to my follow-up emails. English comprehension minimal (well, it *is* China, after all), but you'd expect better given that they were advertising their product in English.