Amazon offers Prime members the Logitech M705 Wireless Laser Marathon Mouse in Black for $19.49 with free shipping. That's a buck under our August mention and the lowest price we could find today by $5, excluding the below mention. It features a 1,000 dpi resolution and up to a 3-year battery life. Two AA batteries are required, included.

A close price: Newegg offers it for $19.99 with free shipping.