Meritline offers the refurbished Logitech M185 Wireless Optical Mouse in Gray, model no. 910-003922, for $9.99. Coupon code "MLCP27GN" cuts it to $5.99. With free shipping, that's tied with last month's refurb mention as the best price we've seen. (It's a current low for a new unit by $6.) This 2.4GHz portable mouse features a nano receiver and requires a AA battery.
A 90-day Meritline warranty applies.