Amazon offers its Amazon Prime members the Belkin Retractable USB Travel Mouse in Grey, model no. F5L016-USB, for $7.84 with free shipping. (Non-members can spend $25 or more to qualify for free shipping; otherwise, shipping costs $5.58.) That's $1 under the lowest total price we could find for this mouse in any color. (Although, we saw a 2-Pack of this mouse for pennies more in April.) This optical mouse features a retractable USB cable and a scroll wheel.

Amazon Prime membership is $79 per year; however, Prime is free for college students for six months, and free for parents and caregivers for three months.