Plastic sets have traditionally had a bad rep, thanks to most of them ... sucking big time. Low quality, unweighted, slipshod plastic pieces are a dime a dozen to this very day. It's all but impossible to re-sell them at a decent price here in Europe e.g., because 95% of plastic sets available today here are of the cheap and nasty variety.
Chiming in with your post, I myself purchased a rather nice Eastern European set, a plastic version of the Ceska Clubocka set, a while ago. While old Soviet plastic sets are widely available on Etsy, Czech ones are few and far between:





These are from the 1980s.
Of the modern plastic sets, I kind of like the Ultimate Chess Set and the Legend Alegria sets a lot, both are high quality. I don't think they'll tip the balance in the perception of plastic sets here in Europe though. ![]()












Plastic sets are usually thought of as being tough and functional rather than particularly aesthetically pleasing. However, I picked up this lovely weighted Soviet set recently, which I reckon is 50's or 60's. If anyone else has any interesting plastic sets, post away!