Best Buy offers the SanDisk Mobile Ultra 64GB Class 6 Secure Digital Extended-Capacity microSDXC Card, model no. SDSDQY-064G-A11A, for $99.99. With free shipping, that’s $1.56/GB and the least expensive 64GB microSDXC card we’ve seen. (It’s also the lowest total price we could find for this model by $49.) Sales tax is added where applicable.