Quantity Discount : 33.53% to 40.50% off 5+ @ 33.53% : 20.26 + 1.01 (5%) = 21.27 10+ @ 37% : 19.20 + 0.96 (5%) = 20.16 15+ @ 40.50% : 18.13 + 0.91 (5%) = 19.04