Amazon has the Logitech G400 Optical Wired Gaming Mouse for
$21.75 w/ free shipping on orders over $25.
3600 dpi optical engine: Get precision targeting, pinpoint accuracy and consistent response at any hand speed
In-game sensitivity switching: Four dpi levels let you instantly go from pixel-precise targeting to lightening-fast maneuvers
1 millisecond report rate over USB: Mouse movements are communicated to your PC at a blazing-fast 1000 reports per second
Built for battle: Comfortable sculpted grip, low-friction feet and rugged long-life buttons that withstand demanding play
Made for PC gaming: Compatible with Windows XP, Vista and 7