PriceGrab via Amazon offers Prime members the SteelSeries Rival 100 Optical Gaming Mouse
in Gaia Green, model no. 62339, for $28.99
with free shipping
. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $8.28.) That's the lowest total price we could find in any color by $4. It features six programmable buttons, customizable CPI up to 4,000, and 30 million click switches.