I think it has to do with early lockdowns with Covid, production slowed way down and then the panic buying began.
FWIW: As of yesterday OSB is now $58, ply $75+ and all plastic and steel either up 40% or non-existent.. Big box store manager told me a number of interesting things. First they are pulling down all tags as prices going up too fast. You ether ask or go into shock at counter. He also says he does NOT go alone when there's a complaint on the floor due to violence potential. Lastly he said they are expecting big drop in construction and home improvement orders as bank loans disappear. Heck I Bought the last log splitter in inventory and was told i was "lucky" to get it at all.
I can easily see MLs and accessories suffering same fate. Think even stuff like a CVA Kentucky two piece stocked kit rifle will average $500+ soon. We are in a transition phase as word about price hikes spreads. Buy what you can while you can still afford it.