That would be the case if we were talking about college, where, 20 years ago textbooks were easily $100, and you had more of them per class. I think the economics work even better there...

But I'm using High School as the example and assuming the district is paying the costs and keeping textbooks and iPads on average for 3 years.

Some people have claimed that iPads won't last very long... but Apple offers AppleCare+ (at least for the iPhone, I expect they'll offer even better warrantees for school districts.)

AppleCare+ will replace a damaged device up to three times for $49 over the course of 3 years, IIRC.

I think the economics are great for high schools, but positively spectacular for colleges (and I'm assuming college textbooks are no longer as cheap as $100, and that the resell situation is as bad- we'd be lucky to get $15 on resale, and the books were bound with glue designed to fall apart over the course of a single semester.)