Write your own text book, save money

I bet this becomes a real trend as school districts become short for cash.
Anoka-Hennepin teachers write their own online textbook, save district $175,000
Instead of mass-produced textbooks, the more than 3,100 sophomores in the state's largest district are learning from an online curriculum developed by their teachers over the summer with free software distributed over the web.
 For the extravagant tuition charged at medical schools it seems they should throw in the course materials for free. No?