I am finishing up the renovation of my 1967 Aristocrat RV. I went to Hone Depot for a couple of poplar planks "1x4x8" and two 4x8 sheets of Birch Plywood. I never checked the price (until I got home). Don't do that unless you don't care how much you are spending. I figured I was approaching $100. I spent the $100 and then some.
I would have done this even if I had done due diligence as I need it to finish the renovation but I could have gone there with eyes open.
Wood working might no longer be an affordable hobby.