Wirelessly posted (Xperia Z: Mozilla/5.0 (Linux; Android 4.4.4; D6503 Build/23.0.1.A.0.167) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/40.0.2214.89 Mobile Safari/537.36)
Is has been 50% off for same day return since day 1....
And if you having same day transit, my humble recommendation is stick with airport express to maximize your stay... Road traffic can be ugly sometime and busses normally include some sort of detour....