Your overdue fines are too high. $2 per hour for a 24-hour book is crazy.
The fine of $2/hour applies only to course readings on reserve that are returned late. Fines are higher for course reserves material because so many students need access to these readings. These materials are usually in very high demand, and when they are not available to other students taking that class, everyone else is disadvantaged. Fines are in place to try to encourage people to bring back materials so everyone in the class has the opportunity to do their readings.