Amazon offers Prime members the Transcend 16GB Class 10 SDHC Memory Card, model no. TS16GSDHC10, for $6.99 with free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping costs $8.25.) That's $0.44/GB and the lowest total price we could find by a buck. It features read speeds of up to 20MB/s and write speeds of up to 18MB/s.