How to reduce textbook costs

There's an interesting article in this week's Chronicle in Review Newsletter entitled One Way to Rein In the Cost of Textbooks: Make Them Free. The author, an emeritus professor, suggests that there are two sets of costs involved in publishing textbooks: the writing/editing/organizing of the book and the publishing/distributing/marketing of the book. He suggests both sets of costs could be greatly reduced using current technologies - the writing by using Wikipedia-style collaboration and the publishing by publishing online. He has 4 textbooks that he's written available online.