I Need Something To Cover Up an unfinished wall?

In my new house i we have an unfinished room that my mom will let me and my friends use to make videos one wall will have a green screen but the other walls just have studs on them (i think thats what there called the wooden things that go behind drywall and insulation So anyway when i showed it to my friend he wanted to cover the walls up with paper which was a good idea until we found out it would cost $47.88 What is a way that we can cover the walls up easily and cheaply <20$ if possible