The tips are part of the overall cost of the system. They only broke it out separately to facilitate their inventory management.
2013 Nissan GT-R - Mine's Mid-Pipe, Mine's Titan Exhaust, AMS Cat-less DP, 1,000cc Injectors, Cobb AP
2013 BMW M5 (DD) - Alpine White on Sakir Orange
2003 Honda S2000 (The Real Fun Car) - Supercharged, all out craziness.