Braindead to think salary is somehow attached to morality. I would say some of the most immoral people are people with a lot of money, and there are countless examples of that.
My logic is that, if you are trying to evaluate whether you'd want to be a politician, consideration of cost/benefit is rational. If you aren't ethical, the benefit of being a politician is a lot higher (because you can get unethical sources of funds). If we want to attract more sane, talented, ethical people, we need to pay more — and prevent blatant corruption like privledged trading.
My logic is that, if you are trying to evaluate whether you'd want to be a politician, consideration of cost/benefit is rational. If you aren't ethical, the benefit of being a politician is a lot higher (because you can get unethical sources of funds). If we want to attract more sane, talented, ethical people, we need to pay more — and prevent blatant corruption like privledged trading.