There may be other influences. Like OSHA, EPA, etc. Thats why the last American lead smelter shut down, massively expensive EPA mandates. Its now recycled lead or a few imports. There is a LOT of lead recovered from auto batteries. IIRC the core on the last one I bought was $18?
I remember batteries selling for $18. No core. Dump it in the alley. Some scrapper might want it.
The black powder market has significantly changed since I bought one. I didn't get much choice back then and had to walk 15 miles to barter pelts for it at the trade store. They even make pellet powder in the bore size now, I hear. Amazing. One for squirrel, two for deer, three for elk. Amazing.