Collectable Plastics?

The environmental problems of plastic pollution are very well known. The Higher School of Economics in Russia has, however, found that investing in plastic toys, can be extremely lucrative. It's certainly better than putting your money into bonds, gold, stamps, stocks or wine (https://www.theguardian.com/lifeandstyle/2021/dec/10/investing-in-lego-more-lucrative-than-gold-study-suggests). Second-hand toys (in particular, Lego, Barbie dolls and certain plastic miniatures) in pristine condition, with their boxes, were excellent investments. For example, limited production runs; special collector editions and rare packs of Lego, rose in value by 11% per year. It just shows what people currently find to be 'must-haves'. I suspect that there will, eventually, be a Lego crash, like that seen of tulip mania in Holland (1634-1637)!