Why are library sales reporting at a lower price than I set?

You might be seeing sales under the Library Pay Per Use model (also known as "Cost-Per-Checkout").

Under the traditional library model, a librarian purchases your book once, paying based on the full list price, and can circulate that copy as many times as they can (to only one patron at a time, of course).

Under the Pay per Use library model, you get paid a (discounted) royalty each and every time the title is checked out by a patron.

Not only do you get paid every time the title is checked out, but this has the added benefit that you no longer have to have a librarian choose to buy your book. They can simply make the book available on the "shelf" at no (up front) cost, giving you crucial visibility and allowing you to drive patron marketing.

You can read a bit more about the specifics of pay per use pricing in schedule C of your distribution agreement within your account.