Input Device Deals & Input Devices for Sale
Of note, a 90-day warranty applies, although it is unclear who backs it
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.
No warranty information is provided.
Update: As a reader found, Better Choice Online via Amazon offers it for $19.99 with free shipping.