Shoot! It wasn't all that long ago that a 128 GB MicroSD card cost about that much. I wonder how they arrived at 400GB as the size for that media card? And I wonder what size will show up for it in File Explorer? I'm guessing it will be 372 GB or thereabouts, as calculated here:
SanDisk announced 400GB MicroSD card for 0-400gb-binary.jpg
SanDisk announced 400GB MicroSD card for 0-400gb-decimal.jpg
I don't really need a microSD that big (or expensive) so somebody else will have to follow up on this!
--Ed--