Pannel is $38... buy in bulk or take some with dents or that didn't come out just perfect. You can get deals if you try. Some times trying to cut too many costs on the front end costs you on the back end. I try to cut costs as much as possible too, but there is nothing I hate more than rebuilding some thing twice because I took the easy road or cheap road the first time.
I have seen where they covered it and made the walls solid and yall are right. The don't try to get out near as hard. Buddy was talking about using some belts off of some kind of machinery that comes in like 3'x 20' or 40'. Two high and its a solid wall.