That's plain naked rentseeking. I'd get them charging a nominal sum to prevent abuse (like "why I'd buy any books if I can just check out everything for free in the library" - virtually nobody ever says that but maybe they're afraid of it) but $55 is way over the cost of an average book, let alone ebook, and expiring them makes zero sense since popular book stops bringing substantial income quite soon so they literally lose nothing allowing the library to keep it.