Earlier quoted context omitted.
Between the limitations and the lack of a used market, ebooks do seem really expensive compared to dead-tree.
There is a huge selection of public domain ebooks (although admittedly less than there ought to be, with the ridiculous copyright extensions). Project Gutenberg has a lot of fairly decent quality .mobi and .epub versions out these days. You can also get a decent amount of stuff from various Amazon programs, like Kindle Unlimited. The selection isn't always perfect, but it's not terrible either. And of course, there a…
Poor formatting, usually, though even commercial ebooks are often bad at that (another reason I don't like them) and at least the proofreading isn't as bad as the commercial ones. Tolerable in some cases—I've read a few.
But if it's a work originally written in a language you don't read, the best translations (easiest to read, most accurate, best balance of the two, take your pick) are usually still covered by copyright. The quality difference between those and what's available from PG is often large.