I'm finding that most fellow academics have very little idea about the pricing and access-levels of ebooks, so I'm gonna share a few things I've learned as a librarian responsible for buying/collecting these ...
First things first, there's nothing inherently wrong about an ebook: in their best form they are highly accessible, adaptable, beautiful, and, yes, go through all of the rigors of peer-review just like a print book ...
& often times, authors can receive a pretty good percentage of ebook sales, which is great, since a lot of academic publishing is essentially subsidized free labor ...
HOWEVER, much like parking meters went from taking coins to accepting credit cards, the conversion to a digital pricing scheme offers many more ways to monetize the same thing—a raise in price was once capped at a quarter; but no longer ...
& what you see on Amazon, a Kindle book for 9 bucks or whatever, is not something an academic library can purchase and distribute to students & faculty (not to mention they are platform-dependent and riddled with DRM) ...
So, what most academic libraries end up purchasing are ebooks managed by very large corporate content curators—EBSCO, ProQuest, etc.—and these have pricing schemes that are ALL OVER THE MAP ...