I am really new here, but i have a IT formation. I know a little about these things.

I do NOT think new users should have as much bandwidth as they want, but i also think the limits should be high. I mean, as high as a "regular" user will use for a good start.

As for paying for additional bandwidth, i think a better solution is to create a way for a user to EARN that bandwidth by POSTING. Not upvoting or commenting, but posting new content that ATTRACTS votes and views.

If the new user just can't get enough followers, viewers or votes for his content, and is just posting a mountain of pictures everyday because of "like, you know", then put a limit there and do not let him cross that limit.

I think that way you incentivate the user to be better in order to advance (a sense of gamification) and, at the same time, attack the problem.

Just my two cents.