The rule of thumb in any business is that the "consumable" portion of the product is where the real profit margin is located. Hardware manufacturers are finding that production costs and pricing are becoming similar numbers.
As for ebook pricing... no comment. According to the publishers it takes more effort to produce an ebook than a dead tree version. Personally I think it comes down to insufficient tools and inexperienced staff. Every book is being hand-crafted instead of using templates, wizards, etc to handle the majority of the work.