Average cost per circulation is AFAIK lower for ebooks than paper books. No additional infrastructure, no additional costs of putting the book into circulation, no leasing fees.
Many libraries lease copies of best sellers at a pretty high rate per copy. According to this article it seems that leasing is more expensive than buying.
http://muscatinejournal.com/news/loc...cc4c03286.html
http://lubbockonline.com/stories/112...12106030.shtml
Leasing a book costs $16 each copy and it is not uncommon for my library to lease 100 copies of the latest rage. The big advantage it seems is that the library will not be stuck with all of these books and nowhere to put them when their popularity wanes and the next wave of popular books arrive.
I would rather see my library buy 10 or 20 copies of an ebook they can lend 27 times for $100 to $200 than to lease 50 at $16($800) that they can only lend till the interest wanes or they need the shelf space. And they often lease 50 and often the interest wanes fast.
A leased book is in my library is always a paperback and the lease price is $16.66 even if the book cover price is $9.99 and there is a cost of $20 per copy just getting it ready for circulation my librarian told me. Does this seem economical to you?
Helen