55 USD seems like quite a bit to pay since I need to supply my own microSD anyway. I'll pass.
I don't get it. Why is this better than just using an SD card?
Because it doesn't stick out from the case at all. Decent idea, I suppose, but micro SD is not designed for the kind of drive activity it looks like their selling this for. If people came to rely on this for storage/backup, I bet they'd regret it at some point once they start burning through what's really cheap, disposable storage cards.
microsd's are not meant for constant read/write. they will degrade incredibly quickly. Its a beautiful project, but a flawed idea.