Amazon offers the PNY 64GB Professional X Class 10 microSDXC Secure Digital Extended Capacity Card, model no. P-SDUX64U1-GES3, for $35.99 with free shipping ($0.56/GB). That's $4 under Best Buy's Deal of the Day price and the lowest total price we could find. (Most stores charge $45 or more.) It features write speeds of up to 20MB/sec and comes with an adapter.