1. Calculating Costs and Break-Even (LO3] Night Shades, Inc., manufactures biotechsunglasses. The variable materials cost is $12.14 per unit, and the variable labor cost is $6.89 per unit. 1. Calculating Costs and Break-Even (LO3] Night Shades, Inc., manufactures biotechsunglasses. The variable materials cost is $12.14 per unit, and the variable labor cost is $6.89 per unit