I worked for a higher-ed startup that was heavily involved in the textbook space for a little over 5 years. There are a myriad of factors that contribute to the high price of textbooks. Some of those factors are:
• The principle / agent problem - Instructors naturally select the course materials for their own courses but typically never need to pay for their own instructor copies. In essence instructors are making decisions for which they generally bear no cost, but which do impact costs for students. Compounding this problem is that, surprisingly often, instructors did not actually know the cost of the materials they selected.
• The cost structure problem - Instructors will sometimes select a textbook to use for a course for only a year, but often they'll use a textbook for longer than a year. Using the same textbook for two to three years for a course isn't uncommon. This has implications re: how much revenue is at stake for a publisher for each textbook sale.
For example - if an instructor is teaching a particular course twice a year (once in the spring and once in the fall), and they use the same textbook for 2 years in a row, and each course has roughly 30 students - then a publisher selling an instructor on a $200 textbook has a value of:
4 courses * 30 students * $200 = $24,000
Or, roughly the cost of some cars. With this kind of revenue on the line for each sale it makes sense for publishers to develop a nation-wide, high touch, hands on, sales force. And a friendly, knowledgeable sales person can be more persuasive during the course materials selection process than a worthy (but distant) affordable textbook initiative that doesn't have an in-person advocate.
• The content discovery problem - Part of the reason why publishers resort to sales teams is because they don't really have any good alternatives. There isn't a great platform for higher ed content discovery. Instructors who want to survey what content might be available for their course have a limited amount of time to make a decision, that decision has large consequences (their entire course might have to be redone for example), and there often isn't very good info about higher ed content (what are the learning outcomes associated with this content? what is the resale value of this content for the student? what do other instructors think about this content? etc.).
• The transient pain problem - Most students complete their college education in 4 - 6 years, which means that (for most) the pain of high textbook prices is temporary. In other words - the pain is temporary for the cohort that would probably be most motivated to solve the problem.