The "flooding" attacks identified by the researchers work by raising the cost of consensus building in a democratic society. Your approach helps deal with the increased cost on an individual level, but it does not help prevent the attacks or counteract their effects on a societal level. i.e. if I can raise the cost of getting quality information from 2 cents to $200 for everybody, you can empower certain people by giving them $200, but you can't bring the price back down to what it was.