Best Buy offers the SanDisk 64GB Ultra UHS-I Class 6 Secure Digital Extended-Capacity Card, model no. SDSDRH-064G-A11, for $39.99 with free shipping ($0.62/GB). That's $7 under our May mention and among the least expensive 64GB SDXC cards of any class that we've ever seen. (It's also a current price low by $15.) Sales tax is added where applicable.

Also available is the SanDisk 4GB Ultra UHS-I Class 6 microSDHC Card (pictured), model no. SDSDQY-004G-A11A, for $4.99 with free shipping ($1.25/GB). That's the lowest total price we could find by $5. It features data transfer rates of up to 30MB/s.