Here is a great infographic that goes through the costs of iPads and iBooks vs. traditional textbooks. It's an interesting comparison.
Related:
Apple Announces iBooks2 E-Textbooks - my initial thoughts
On device apps/software vs. web apps - which is better for schools?
Obama wants all students using digital textbooks - I ask where the $ are coming from
Resources to Replace Textbooks
What I use with Physics classes instead of textbook
CK-12 Free Digital Textbooks
150 Free Textbooks
The How's, Why's and Value of Educational Technology
10 Important Skills Students need for the Future
Resources to Replace Textbooks
What I use with Physics classes instead of textbook
CK-12 Free Digital Textbooks
150 Free Textbooks
The How's, Why's and Value of Educational Technology
10 Important Skills Students need for the Future