You want cheap, you can make one for around $8-$9. You can make it any size you want and it will last for years. Get 2 threaded rods, 2 pieces of 2X8s, drill a hole in each end for your threaded rods, get washer and nuts that fit your threaded rod. Then get a bunch of cardboard boxes and lay them on top of each other, flat. Once the space is filled up between the two 2X8s, tighten the nuts down and compress the cardboard. Once you tear up one side, turn it around. Last forever.