Kawasaki ZXEFF Ninja ZX-6R Options, Equipment, and Prices. Select Kawasaki ZXEFF Ninja ZX-6R Options. Find the trade-in value or typical listing price of your Kawasaki Ninja ZX-6R at Kelley Blue Book. The Ninja ZX-6R features the most up-to-date sportbike and racetrack technology offered by Kawasaki. Its three-mode Kawasaki Traction Control (KTRC) system is.