I figure a low grade is punishment enough. Have students reconcile actual cash in hand with balance in Cash Accounting Sheet. Have them write a paragraph to explain any discrepancies. The note is assignable to other parties. Scarcity is the basic economic problem and choice is its consequence.
All choices involve benefits and costs.
When people choose, they accept one alternative and give up another. Deciding to make no choice is a choice and has consequences. There will be consequences to students' decisions measured in class currency. They base it on how many weeks are left to factor in rent savings to themselves or potential rental earnings if they are purchasing it as rental property. They are making an informed choice and their choice does affect them and others.