Our first play done this way was Stone Soup and so now we have five nice pieces of "town" scenery. These can be used for many other play productions -- so versatile.
We are currently putting on the Nutcracker so we are painting five pieces of "house interior" and five pieces of "candy village". One of the house interior pieces, a fireplace, can definitely be used in other plays as well! We also did an nice grandfather clock.
Be creative -- I got five light blue sheets for the candy village and we only had to paint on the houses and trees because there was already a sky! For the house interior, I got two off white sheets and three striped sheets. The striped sheets are the wallpaper. They didn't need to be painted at all! One of the off white sheets was used to paint the fireplace scene. The other holds the grandfather clock.
We just went ahead and used tempera paint so don't think this will be too expensive. You could also sew some details onto your sets if you were feeling extra creative (and had extra time), such as putting sequins on the snowflakes to give them that added sparkle. Lay your sheets out on a tarp in the classroom for painting and then hang them outside for drying. I hung ours over the chain link fence that surrounds the blacktop, and used more safety pins to be sure they stayed in place while they were drying and didn't blow away. Easy easy easy easy and -- my favorite -- inexpensive! Not only that, instead of using rolls of paper to create backdrops each year, I am ecstatic that we only have to paint the Nutcracker sets once and then we will be done.