College & Research Libraries has released an e-print of "Cost Differentials between E-Books and Print in Academic Libraries."
Here's an excerpt:
A survey conducted at Auburn University at Montgomery (AUM) has confirmed for academic libraries the work of Gray and Copeland on e-books being more expensive than print for public libraries. For AUM, the mean cost for e-books are significantly higher than for the print counterpart of those titles. The cost differentials between the two formats show e-books as being consistently higher than print in initial price. This consistency holds true across all LC classifications, regardless of whether or not the title is published by a university press or a commercial press.