I paid $80 / sheet x 2 for 3/8 sanded plywood 2 weeks ago.
I also made a mistake last year when working on a basement subfloor and bought 3/4" (23/32) PT 4x8 sheets of plywood (at normal prices).
I had to have HD cut them in half for transport.
Then I was reading my vinyl planking install, and they recommended against having PT as the subfloor.
So with these eight 4' x4' sheets in the way for a year, and tired of moving them, I put them on CL at $10 per half sheet to move them.
I had a half dozen calls within the first few hours. They were gone to the first guy that called.
I have a big job next spring insulating the underside of an enclosed porch that is open to the roof sheathing with pre-fabbed trusses dating from the early 60's. They were stained and have a rustic look.
Plan is to place 3" solid foam board between the rafters and cover with sections of stained plywood to maintain the rustic look.
The area is about 600 sq. Ft without waste I will wait and hopefully the prices will normalize.
Cheers, nashbalto