If you're not lost... It's not an adventure! Member since Jun 2014 3774 Points Moderator
Mind you... having just done a little online truffle snuffling for info and possible retail outlets for them, there doesn't seem to be many anyway...
... and the Beatles one that's in the link you provided isn't exactly cheap: £72, and already described as "Rare".
I also get the impression that these are specifically for a high end proprietary mp3 player branded: Astell & Kern (thin I got that right, although I may be wrong.)
Not that I plan to buy anything in this format, but if it's a micro SD card, with .wav or FLAC files at 44/24, wouldn't it be playable in any micro SD drive in any computer? It would seem they'd be shooting themselves in the foot if it was only compatible with one kind of player.
If you're not lost... It's not an adventure! Member since Jun 2014 3774 Points Moderator
I get the impression that the brand in question is the kind of manufacturer who aims their products at the same kind of people who pay 10 thousand quid for a diamond encrusted mobile phone.
...Or those other ridiculously expensive mp3 players that are made of laser cut plutonium cases :)