Anthony Herrera recently fulfilled his long-time dream of opening a gym that offers spinning exercise classes for $5.76 per person. To differentiate his gym and better serve his clients, Anthony provides a towel, a bottle of water, and an after-workout protein shake to each person participating in a class, at a cost of $2.59 per person. Anthony employs three part-time instructors and pays them each $1,144 per month. He also pays himself a monthly salary of $4,268. Anthony's other monthly costs are $1,560 for rent, $1,418 for depreciation on his 32 bikes, and $1,840 in utilities and insurance.

What is Anthony's contribution margin per unit?