To the best of my knowledge these are the current terms at which library ebooks are offered by the big publishers...
Random House, no expiration...
Titles available in print as new hardcovers: $65- $85
Titles available for several months, or generally timed to paperback release: $25-$50
New children’s titles available in print as hardcovers: $35-$85
Older children’s titles and children’s paperbacks: $25-$45
Penguin, titles expire after one year
Pricing is "similar" to what consumers pay.
HarperCollins, books expire after 26 loans...
Not sure on pricing, but IIRC it's whatever full retail list price is at the time.
Hachette, no expiration...
The initial price will be three times the highest-price edition then in print. One year after publication, the purchase price will drop to 1.5 times the highest-price print edition.
Macmillan, Two years or 52 lends, whichever comes first...
Unsure on pricing
Simon & Schuster, titles expire after one year.
Not sure on pricing