Amazon offers the GreenWorks Pro 80V 21" Cordless Lawn Mower, model no. GLM801600, for $200.23 with free shipping. That's the lowest total price we could find by $76. It features Smart Cut technology (which adjusts the power based on the thickness of your grass), height adjustment from 1-1/4" to 3-3/8", up to 60 minutes of run-time per charge, and rear bagging and mulching capabilities.
Note that a battery and charger are not included.