Home Depot offers the Ego 21" 56-volt Lithium-Ion Cordless Battery Self-Propelled Mower, model no. LM2102SP, for $549 with free shipping. That's $50 off list and the lowest total price we could find. Features include a 60-minute cut time, 60-minute charge time, 3-in-1 mulching/bagging/side discharge system, and 2-bushel collection bag.