There is a perception that digital textbooks should be cheaper than printed ones. From what I have seen and understand, not only is this not the case, but there is typically good reason. For one, the print and distribution costs are not 50-75% of the cost of creating a book, despite expectations or perceptions. Not that there is not room for further supply chain or production efficiencies, but frankly, just because it is electronic does not mean it will cost less.
To back up this observation, a recent study by CampusBooks.com reports that renting or buying a used textbook was cheapest for 91.6% of the top 1000 textbooks for back-to-school. The other 8.4% of the time, e-books were less expensive -- somtimes significantly so.
On a separate note, while something of a press release, the story does point out (once again) the importance of stores being a part of price comparison. We know students engage in price comparison, and that the trend to do so is increasing. If stores do not participate in such comparisons they are out of the equation from the perspective of purchasing decision.