Not sure the price of the siding per sq ft, but 3 yrs ago (a lifetime I understand) I looked at tongue and groove pine, smart siding and OSB (that was expensive at that time). I decided on AC “cabinet grade” plywood. At that time it was 32.00 a sheet and was a bit more than OSB, way cheaper than tongue and groove and just slightly more than the smart siding. I want to say like .10 cents a square foot more at that time. I coated it with clear, interior satin polyurethane and haven’t looked back. It is 3/4”, can hang anything just about anywhere, and looks amazing. Oh yea, I briefly considered tin on the inside, and quickly turned that down. Noise and ability to hang things would have made that a huge no. I did, however use it for the last 2’ at the top of my walls. Seeing how it was indeed cheaper than the plywood I used. BCX was available, but was 29.00 a sheet, so I spent the extra 60.00 and went with the AC plywood. here pare a few pictures of my interior when it was done.