Newegg offers the refurbished Logitech M185 Wireless Optical Mouse in Gray, model no. 910-003922, for $4.99 plus 99 cents for shipping. That's tied with last week's mention as the best price we've seen and $2 under the lowest total price we could find for a refurb. This 2.4GHz portable mouse features a nano receiver and requires a AA battery. Deal ends March 30.
A 90-day warranty applies, but it's unclear who provides it.