Today only, Amazon offers its Prime members the SanDisk Ultra HD 16GB Class 10 Secure Digital Card (pictured), model no. SDSDU-016G-U46, for $17.99 with free shipping. (Non-members can spend $25 or more to qualify for free shipping; otherwise, shipping costs $8.02.) That's $1.12/GB and the lowest total price we've seen. (It's also a current price low by $2).

Also available to Prime members is the SanDisk Ultra HD 32GB Class 10 Secure Digital Card, model no. SDSDU-032G-U46, for $29.99 with free shipping. (Non-members can spend $25 or more to qualify for free shipping; otherwise, shipping costs $8.02.) That's $0.94/GB and the lowest total price we could find by $3.

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.