mwave offers the Microsoft Wireless Mobile Mouse 3000 in Pink, model no. 6BA-00025, for $13.95 with free shipping. That's the lowest total price we could find now by $8, although it was $2 less in February. This 4-button mouse hides a tiny snap-in USB receiver that plugs into your laptop.
Microsoft (6BA-00025) (882224750141) Wireless Mouse is also available at these stores