I think it is ESPECIALLY important for the high level characters, as they would represent the biggest gold sink. Usually they are those who have the most money, and they are desperately trying to reach level 34 or 35, and thus they would spend most of the money for XP.
The lottery is a bad replacement for that, because the motivation (=participation) is not high enough, and it pumps money back into the system.
With 10 XP per gold would still make high level characters impossible. So stop downvoting poor Tom, his suggestion isn't that bad at all. Perhaps you don't think it is a good one, or you wouldn't use that feature if it'd be implemented, but sure as hell it is not one of those retarded suggestions which deserve being downvoted.