B&H Photo Video and Adorama have a great deal on the Lexar 64GB Professional 1000x UHS-II SDXC (Class 10, UHS Speed Class 3) — it’s only $24.99, 50% off.
This is a fast UHS-II card supporting up to 150 MB/s read and 75 MB/s write in cameras with UHS-II interfaces. This card is backwards compatible to UHS-I interfaces.