The ones I found on Amazon are pricey for such a simple item and seem too plastic (I checked and it was 90% polyester mixed with another plastic). There are exceptions but can't be delivered until next year. I asked AI but it just found similar ones. I found the thread below where the top comment says Uniqlo long johns will be too cold for Nikko where I'll be going before New Years. I'm used to buying a 3 pack of cheap cotton ones that last for years but maybe that's because I'm from a cold country.
Has anyone found a good and cheap option?
https://www.reddit.com/r/JapanTravelTips/comments/17oyacy/uniqlo_heattech_enough_for_travel_in_japan
by dendaera