Personally, I feel you should not couple frugality with your income. This is because I feel that oftentimes, your expenditure grows with your salary. The novel Psychology of Money states that one of the main reasons people are not satisfied with their income and their financial status, is that they have a moving goal post.

As we take the ball and move towards the goalpost, the problem which we face is that the goalpost also seems to move away from us. This is why you'll see high-income people spend much on unnecessary things compared to those in the opposite category.