Monoprice offers its Monoprice 6-Key Gaming Mouse with Adjustable Sensor Rate for $8.32 with free shipping. That's $9 off and the lowest total price we could find. This corded mouse features adjustable DPI sensitivity with 800, 1,200, 1,600, and 2,400 DPI.
Also available is the Monoprice M19 3-Button Wireless Optical Mouse for $6.68 with free shipping. That's $19 off and the lowest total price we could find. It requires two AAA batteries, included.