How much money is spent on new curriculum that either fails to teach or riffs off of curriculum that exists beyond copy-write and free to the public?
Don Potter Education Pages
"These pages are dedicated to the dissemination of materials of value to parents and educators interested in improving the quality of education in America and throughout the English speaking world. I have published PDF files of valuable books from the past. There are select links to web sites and articles that I judge as being particularly valuable."