Question for anime fans: Interstella 5555?

Interstella 5555: The 5tory of the 5ecret 5tar 5ystem: worth picking up?  I watched ‘Superheroes’

…because I’m apparently in a Daft Punk mood; but is it worth it to just get the whole thing?  I’m assuming that I don’t want to subscribe to whatever service there that Amazon is flogging, though.  I don’t know why they just won’t let me buy a digital copy outright.