Newegg via eBay offers the factory-refurbished Logitech M185 Wireless Optical Mouse in Gray, model no. 910-003922, for $5.99 with free shipping. That's the lowest total price we could find for a refurb by $4, although we saw one for a buck less last month. This 2.4GHz portable mouse features a nano receiver and requires one AA battery. A 3-year Logitech warranty applies.