I have absolutely no idea. Corporate greed? Housing booms across the planet causing everyone to compete for a finite level of raw material output? Hoarding ala toilet paper during covid?

There was a crazy increase in prices on stuff when covid disruptions were going hot and heavy, but they relaxed and sorta fell mostly in line with what they were pre disruptions. I cant recall the price on copper but i know at one point the local lumberyard was getting over 75 bucks for a sheet of 23/32 plywood. Its about 50 now but it was less a month ago. Its on the increase again.

It really does make it hard when literally every part you use goes up, constantly.