Amazon offers its Amazon Prime members the Logitech K120 Keyboard, model no. 920-002478, for $9.99 with free shipping. (Non-members can spend $25 or more to qualify for free shipping; otherwise, shipping costs $6.17.) That's the lowest total price we could find by $3. Features include a spill-resistant design and USB connectivity.

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.