Quantity Discount : 28.75% to 36.25% off 5+ @ 28.75% : 603.81 + 108.69 (18%) = 712.50 10+ @ 32.50% : 572.03 + 102.97 (18%) = 675 15+ @ 36.25% : 540.25 + 97.25 (18%) = 637.50