Question on build material?

What is best for best price on walls? I'm looking at around half inch 4 X 8 common ply! At $30 a sheet. Is there any way to go thinner and be cheaper? Or will that be a problem?

I just paid $10 a sheet at homedepot. You could also use 2x4's and panda paper as walls. thats what I got going

They are $30 a sheet here in Co

Im in the springs, I just bought 10 sheets of it at home depot for $10.75 a pc

I would just panda it but I'm going fully sealed with co2

Academy home depot?

yep