Are we simply creating a problem where none truly exist? I never upvote my own comments, and almost always my posts - by default. With the increased energy level one vote requires, I may just disable the self-upvote at submission.
The natural breaks for abuse are codified -- in the code. Everything else is codified in our soul. And it's visible, transparent and it speaks to character.
When I see a greed account, I usually do not follow - and once spotted, will treat any submission by such account with the credibility it has earned, or unearned.