Staples has NXT Technologies Optical USB Mouse (Black, NX60905) on sale for $3.24. Shipping is free.

Features:

• Stylish and comfortable optical mouse is perfect for everyday use at home or office
• USB wired connectivity allows the user to immediately connect and begin using the mouse
• Suitable for both right- and left-handed users
• Contoured grip provides optimal comfort for extended periods of use
• Optical sensor provides reliable tracking