My idea was to demonstrate the "crusade" by crushing the overpriced textbook with the iron ball. The logo says: "Yeah - he just crashed it - Now, do you dare to buy another overpriced textbook, do you?!"
There are still some adjustments and polish required but I saw the contest in the last moment so I didn't have enough time to clear these details. However these are fixable in a coupe of hours if you like my idea of course.