Newegg offers the refurbished HP x4000b Bluetooth Wireless Laser Mouse, model no. H3T51AA#ABC, for $9.99 with free shipping. That's tied with our mention of a new mouse from last spring as the lowest total price we've seen. (It's a current low for a refurb by $3.) It features an LED battery indicator and purports to have a nine-month battery life.
A 90-day warranty applies, but it's unclear who backs it.