Our school recently purchased ELMO Mo-1 document cameras for our classrooms. The price is more reasonable through Amazon than through ELMO themselves. If you don't mind a bit of color, the pink model is even less expensive. We also have some TT-12 ELMO's on campus. In comparison, they have a much stronger magnification zoom, but they also have a larger footprint. Also, the price is a bit higher. We find that the larger model works really well for teachers of Science, and the smaller one suits the needs for all other teachers. I'm appy to answer any other questions you may have.
Click the links below to find the 2 models on Amazon.