A:Answer I don't think these are "hard cards" actually in the store, but rather a digital transaction code.
I could be wrong: years ago, they used to carry the World of Tanks prepaid cards. So possibly these are in the store, too.
I've just never really looked for them, since I can just as well do the transaction safely and securely across Best Buy's site and they email you a digital claim code to redeem on the game's website.