I can testify to that. When I worked in SFUSD they had just adopted a new Algebra 1 text book that was probably four times as big as the books in our days. The book was full of random full-page images of things like giraffes. I remember telling my students to be careful with the books as the replacement cost was listed at $120.
However, as much as I see the current textbook industry as predatory racketeering that needs to go, I also oppose IPADs in schools and consistently advise schools against purchasing them. As far as k-12 education goes, netbooks are vastly superior technologies at a fraction of the cost.