The Kindle pricing is all sorts of wrong. Is it the publisher? Thankfully, I didn't buy a Kindle and so my e-reading on a phone used for many other things. I'll only read sanely priced or free public domain books.
The Kindle price is so high because of price fixing by Apple and the publishers. Read the following WSJ article. Sentinel is a subsidary of Penguin which is charged in the Anti-Trust Case. This price is set by Steve Jobs and Apple, not Amazon. Just another good reason not to support overpriced Apple products. Now they are going after the rest of us.