RC Superstore via eBay offers the Spektrum DX4S DSMR 4-Channel Auto Radio, model no. SPM4020W, bundled with the SR415 Receiver and SRS4210 Receiver for $159.99 with free shipping. That's the lowest total price we could find by $71. Features include frequency-agile DSMR 2.4GHz technology, 30-model transmitter memory, independent AVC steering and throttle assistance, and three grip sizes. It includes four AA batteries.