Amazon offers its Prime members the Kingston 16GB Class 4 MicroSDHC Flash Card, model no. SDC4/16GB, for $5.99 with free shipping. (Non-members can spend $35 to qualify for free shipping; otherwise, shipping adds $8.05. via Rakuten Shopping charges the same.) That's the lowest total price we could find by a buck. It features a minimum data transfer rate of 4MB/sec and includes an SD adapter. Deal ends May 2.