Quantity Discount : 33.46% to 40.50% off 5+ @ 33.46% : 17.74 + 0.89 (5%) = 18.63 10+ @ 37% : 16.80 + 0.84 (5%) = 17.64 15+ @ 40.50% : 15.87 + 0.79 (5%) = 16.66