Amazon has the Diono Cambria Highback Booster Car Seat (Raspberry) for $42 with free shipping. List price: $80. Features 100% polyester, complete side impact protection with deep headrest and full body sidewalls reinforced with EPE foam and a double-walled construction.
Has good Amazon Reviews.
Walmart has the Boss Audio ATV25B - Powersports Plug & Play Bluetooth Sound System with 450 Watt Built-in Amplifier for $129 - $24 off with in-store pickup = $105 with free in-store pickup. Features soft dome diaphragm high-performance tweeter, 3.5mm aux-in compatible with audio output of iPod/iPhone, smartphones and MP3 players, speakers powered by internal amplifier.
Has good Amazon Reviews, where it sells for $107 with free shipping.
eBay has the 20" Bicycle Electric Motor Conversion Kit (Black) for $200 with free shipping. List price: $421. Features powerful 1000W 48V brushless hub motor that allows up to 45 KM/H top speed, kit includes motor controller, speed throttle, power break lever, wire harness, pedal assist sensor.