It took me a minute watching the presentation to get what I think they are on about, although I'm still not sure. It states that the benefit to the school is the student gets to keep the book which could initially be purchased via a redemption code given by the school, so although the price for anyone to buy is $14.99, this is not necessarily what the school will pay, the trade-off would be if the apple way is more cost effective, but for the student point of view it certainly seems more favourable as you get to keep the book which is otherwise handed back!
Soon, students will check out iPads. You can load custom firmware that locks out certain portions of the operating system (system settings, for example) even far beyond what the Restrictions allow.
When I was in high school, graphing calculators were $300 a pop. An iPad is much more versatile and $200 more (pricing and size subject to change of course) - A lot of K-12 districts are going to jump on this.