Sentence:  He had heard people speak contemptuously of money: he wondered if they had ever tried to do without it. He knew that the lack made a man petty, mean, grasping; it distorted his character and caused him to view the world from a vulgar angle; when you had to consider every penny, money became of grotesque importance: you needed a <WSD>competency</WSD> to rate it at its proper value. 
Meaning of the word marked with <WSD> tags:  A sustainable income.