Amazon offers Prime members the Nyko Charge Base 360 S for Xbox 360
with free shipping
. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping adds $4.98.) That's the lowest total price we could find by $8. It includes two rechargeable batteries with up to 25 hours of playtime each, stores two Xbox 360 controllers, and can charge via USB or AC power.