Famous authors deserve some sort of gratuity. Splurging for most is ordering pizza on a day other than Thursday. For others, it might be that heralded cup of coffee from the Cage on the way to class. We do not have the budgets for hundreds upon hundreds of dollars in books. But to do the work and get the grade, you need the book.
Alternatives are limited.
The St. Olaf Bookstore also offers a price break to those that order early. That's another four pizzas. There are some professors that have thought ahead and worked to minimize costs. For example, limited numbers of books are on closed-reserve at the Library. Over in our mother country, things are handled slightly differently.