Newegg via eBay 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 last month as the lowest total price we've seen for a refurb. (A new one costs at least $7 more.) This 2.4GHz portable mouse features a nano receiver and requires a AA battery.
No warranty information is provided.