Quantity Discount : 28.74% to 36.25% off 5+ @ 28.74% : 65.82 + 11.85 (18%) = 77.67 10+ @ 32.50% : 62.35 + 11.22 (18%) = 73.57 15+ @ 36.25% : 58.89 + 10.60 (18%) = 69.49