A few things to remember;
- With pbooks there is a constant, sunk, setup cost whether the production run is large or small. Ebooks don't require this setup printing cost & could allow smaller runs of speciality books at a cheaper price, thus allowing a greater range of books to reach the market.
- With pbooks there is the cost of the retailer, his facility & employee paychecks and his profit (as well as his losses due to not selling his inventory - said losses may be born by the publisher). These costs do not apply to ebooks.
- Some (maybe most) of the computer resources that ebooks require are already in place with the publishers. He just will need a new paradigm on computer usage.
- The shift towards ebooks & away from pbooks would be gradual. This may mean that ebooks start out at a higher cost due to new, untried methods but should eventually drop significantly.