its a nice idea but i think you said it wrong and too extreme, Gabe.
how about a discount of say 10% (instead of saying that the bad people pay full price, nicer spin)? its a small enough ammount that few would not buy the game, even if paying full price. and how about $5 for voice for everyone, except it may get waved after spending a while in the community.
the extremes you are talking about ($100 for voice for bad people) is absurd, you would remove the trouble makers in theory but in practice this will only go off a user based rating system, which will and has never worked 100% and therefore flawed, leaving a broken community, filled with idiots.