I realized I hadn't updated in several years my post https://mathematikoi.net/p0/index.html on the textbook pain multiplier. Still haven't, but at least I've made the new graphs, the basic one I attach here. It shows the crazy cost increases of textbooks in the US from 1980 to 2025 hit a bit of a wobble 2017-2024 due to #OER, I assume, but then jumped way up again recently.
Note some recent BLS data is missing, I guess from US federal govt chaos.



