Correct me if I'm wrong ... but publishers use desktop publishing packages to produce the book. Gone are the days of needing "film" and laying these things out by hand.
That said ... producing an ebook from desktop publishing files has to be almost as simple as producing physical books from desktop publishing files. What's more ... there are no paper costs or printing costs associated with the ebook.
I can understand a publisher wanting to have a hard cover copy of a book out first at more money, and to release a paperback copy a year later. However, I can't equate the production of an ebook ending up costing MORE than a hard cover book. It's just not reasonable.
Now, I generally borrow books from the library ... but I do purchase books from time to time. I simply won't pay upwards of $20 for a "just released" book, preferring to wait until the price has dropped ...