Cheap sets? We built rolling wooden frames that were exactly as wide as a roll of heavy duty natural (no glaze) butcher paper: 3' wide, 8' tall, and 1.5' thick. Invest in a staple gun and some great little wheels and learn to paint in 3-D (or don't and say it's a "concept"). For each show, we would roll out a fresh sheet of butcher paper, paint it on the ground, then staple it to the wooden frame. Because you're only dealing with scaffolding, the frames are incredibly light weight. My elementary students could move them with no problem. Because they're 1.5' thick, they don't tip over. Best yet? They move, they spin, they're two-sided... and they're CHEAP! Once you build them, you have them. You can even build them so they lay flat when you're finished. You can make little latches to connect them together or just stand them side-by-side. Need a door? Pull them apart! Worried about slippage? Get wheels with little foot-pedal locks. We built a few of them 3' thick and added a shelf to the front to hold props. This created a kind of stair-step effect. Kids can even walk through them (carefully) if you have no backstage area. At the end of the production, you can toss or recycle the old paper part of the set (or put it away for safe-keeping). Your only expense for your next show is more of your school's (hopefully free) butcher paper and some tempera paint! Go to my page (Hannah Kohl) and look at my photo album for "Productions in Mexico" - you'll see examples of our rolling frame sets being used in multiple productions: as a flower shop in Gardenia!, as wallpaper in The Sound of Music, and as a castle... or (by repainting the windows) a nunnery. Best wishes! Hannah