I agree with some others, try not to eliminate ceramics as an option for middle school students. I find it is not the clay that is expensive, but glazes can be. I use a clay that fires while that I get locally from Georgies. In this way it allows use to use all types of other finishes. On greenware you can use slip, do scaffito techniques, etc. On bisque you can use diluted tempera to stain, paint with tempera and seal, paint with acrylics ( I had a 7th grader this year create a beautiful work and he painted with metallics) or do very cool saggar firings!
Hopefully you can leave it in for these students even with the shrinking budget!
creatively,
Linda Kieling
(middle school in Oregon)