Carla Parties sells supplies for celebrations. One item that sells particularly well is the multi-purpose graduation hat-it doubles as a hat and as a serving tray-genius! Carla Parties' manager pulled some of last year's numbers to get an idea of what this year's performance might look like, as follows. Sales volume 2,160 units Selling price $17 per unit Variable cost of graduation hat (from supplier) $6 per unit Variable commission for salespeople $2 per unit Fixed selling, general, and administrative costs $13,000 Carla Parties did not have any fixed product costs last year, as it is a merchandiser.