Allreli via Amazon offers the Allreli SK-T2 USB Optical Gaming Mouse, model no. ALLSKT2BK_1013, for $19.99. Coupon code "PTIKKGZO" cuts it to $11.99. Plus, Prime members receive free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping adds $8.22.) That's $28 off list and the best price we could find. It features four DPI sensitivity settings (200 to 4,000 DPI) six programmable buttons, braided 5-foot cord, and a color changing LED light.

Note that the drivers required to customize buttons do not support Mac OS X.