B&H has the Samsung 256GB EVO+ microSDXC memory card for $85.95 (reg. $130.95). I’ve actually been using the 128GB version of this card this week shooting with the GoPro HERO6. It’s a great card that seems to be a good fit for GoPro cameras. Check it out here at B&H Photo.
Learn more about SD card specifications and features in my article, Demystifying SD Cards.