I think that e-book pricing needs to change somehow to accommodate for the following facts
An e-book requires proofreading and editing, no doubt. Here the costs are similar to physical books. There are however models in which the readers can help. The author can far easily update an e-book based on reader feedback and subsequent readers will be spared the mistakes. This can drive down the cost of preparing an e-book.
An e-book is much cheaper to distribute and requires no middlemen along the way. This does mean that some middlemen will be without jobs. They’ll probably find a job that is more creative, like writing a book. We can hopefully dismiss that as a temporary phenomenon.
An e-book is hard to lend, a physical book is easier, which means that a physical book will be read by several people during its lifetime. Some physical books are hoarded by their owners but let’s assume that several are shared. This means more e-books will be sold than physical books. That should make them cheaper. A widely read author or publisher will have more buyers, which means each can pay lesser. Physical, school or college text books are particularly widely shared, and should see higher price reductions in their e-book avatar.