I think presenting costs as a rough “per user/player” calculation might be more effective than presenting just the total cost. That way people are reminded of their own personal resource usage, which seems like a more manageable/tangible number, and it can be accompanied by the broader stats since of course not everyone voluntarily pays (and some people pay more than their fair share).

Valve has some great talks on monetizing free games. People will pay for social features that don’t change the game mechanics. E.g., make every donor’s avatar visually different, so people acknowledge they’re good people. E.g., wear a gold chain around their avatar’s neck or a feather in their hat. Or render them with more polygons! Larger donation = more polygons?! Makes sense to me. Or sell weapons that are the same as regular weapons but trigger fancy death scenes when they kill.