Nice analysis! I don't think cards will become super valuable in the near future, because everyone who wants to spend tons of ETH on cards probably already did just that and has most if not all of the legendaries in their collection. On reddit I saw people speculating that prices of certain diamond rares may go up to 50ETH, but this can only be possible if there are some rich collectors out there who are willing to spend that much only because a card is diamond...yeah we'll see.