Walmart offers the Swagtron Swagger-1 Collapsible Electric Scooter, model no. AA-90088-2, for $299.99 with free shipping. (Amazon has it for the same price.) That's the lowest total price we could find by $100, outside the below offer. This carbon fiber scooter can travel up to 17 miles on a single charge and features a 250-watt motor, cruise control (at up to 15 mph) and a 250-lb. weight capacity.
A close price: Hayneedle offers it for $305.99 with free shipping.