cheap collision estimating software for a school?

Hey all,
I took a collision class to help save it from being cut from the high school, but am fairly new to the industry. I'm trying to set up a good curriculum and was wondering if anyone knew of a cheap/free estimating software to teach from. I have the old books but was told that they were fading out. I researched the software but boy is it expensive. Don't think the school will cough up that kind of cash with an already expensive program.

Any ideas??
Thanks