> e-books can be purchased pretty much anywhere in the world That would be true if and only if there's an ebook version for the book you want. There are lots

> e-books can be purchased pretty much anywhere in the world That would be true if and only if there's an ebook version for the book you want. There are lots of books (even essential works for some fields) out there for which there are no legal ebooks. Your only hope would be to get a digitized PDF from zlibrary or libgen. Even if you had the cash to spare for purchasing it, you can't. One interesting case is what happened with books such as James Livingston's "Modern Christian Thought" (Fortress Press). I need it as an ebook. Well, they have (and I have purchased) volume I as an ebook, but they have Volume II only as paperback. I reached out to the publisher to inquire whether they are going to release Volume II as an ebook. Someone there answered, telling me that they "forgot" to release Volume II in electronic format, and that they plan to release it "soon". I'm still waiting...