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 our mention from two weeks ago and the lowest total price we could find for a refurb by $1. (A new one costs at least $6 more.) This 2.4GHz portable mouse features a nano receiver and requires a AA battery. Deal ends February 5.
A 90-day warranty applies, but it's unclear who backs it.