Replying to Building A Box With Whiteboards!!

So I want to build a box for my yard, but as always the problem for a homemade box is a surface, unless you have money falling out of your pockets. So I got the idea to use around 15 little whiteboards (the ones you use at school) as a surface. I have no idea if this would work or not. It seems it might either not be slippery enough or would scratch up so fast that It wouldnt be worth it. Now i could get 15 ft of material, thats 15 whiteboards a foot long and 8 in wide, for around 25 bucks. Should I try it, and if not how much am I going to end up spending and where can I get another surface.