I agree, that part might be illegal because adolescents cannot legally consent (in most cases). So there's a chance there, but my guess is that an adolescent isn't going to be making a $48k MTX purchase (they aren't old enough to legally have debt, and probably not old enough to earn that much).

In general though, I can't think of any law this violates.

Microtransactions in games mainly played by minors should be illegal, yes (and in some countries they are), as they're basically a form of gambling... but people giving CIG money are mostly those who played Wing Commander back in the nineties and want a modern version of that, so there's little risk of kids being involved, at least until the games are properly released (and, even then, they're PC exclusive, and most kids are probably on consoles or mobile devices), at which point as I understand it these ship sales are supposed to stop... and there's nothing micro about them... if I recall correctly the smallest package (which would get you a base ship and the two games) goes for about $40...