Walmart offers the Samsung 64GB Evo UHS-I Class 10 microSDXC Card with Adapter, model no. MB-MP64DA/AM, for $16.27. (Find it under "more sellers". Amazon charges the same with free shipping for Prime members.) Choose in-store pickup to avoid the $4.97 shipping fee. That's $2 below our December mention and the lowest total price we've seen. (It's a current best by $4.) It features data transfer speeds of up to 48MB/s.