I bet that soon--within 10 years--the standard will be for schools to loan ereaders to students instead of giving them textbooks and students will use ereaders rather than buy textbooks.
The most basic Kindle currently costs only $79
. The Nook Simple Touch currently costs only $99
. Even at that price, it seems clear to me that schools would be much better off financially to purchase a collection of ereaders rather than repeatedly buying new textbooks, not to mention the other benefits such as saving space and being able to get new cheap digital versions of textbooks rather than being stuck with old textbooks until they wear out. But the schools would probably save a lot more money in other ways too. Namely, they could surely get a better price by buying in bulk than one would get buying a single ereader: They could get a better price if needed by buying preowned ereaders rather than new top-of-the-line models and also by allowing the numerous students who already own ereaders to use their own and only loan ones to those who need them. If they really wanted, they could also require students who can afford it to buy their own and only use the loaner ereaders for financially poorer students, but they may or may not fly with students, parents and/or voters.
I think the only thing holding this back is that the schools do not need to make the choice until it is time to buy new textbooks. If it isn't broke, don't fix it. Until they need to greatly replace their textbook supply, a school can just hang on to what they already have.
Of course this is all just my guessing.