Audiosavings via Walmart offers the Rockville USS8 8" Slim Under-Seat Active Powered Car/Truck Subwoofer for $99.95 with free shipping. (Rockville charges the same.) That's the lowest price we could find by $8. It features 150-watt RMS power output (600-watt peak), 15Hz to 125Hz frequency response, and 3-ohms impedance.