feast or famine
Also, either feast or famine. Either too much or too little, too many or too few. For example, Free-lancers generally find it's feast or famine—too many assignments or too few, or Yesterday two hundred showed up at the fair, today two dozen—it's either feast or famine. This expression, which transfers an overabundance or shortage of food to numerous other undertakings, was first recorded in 1732 as feast or fast, the noun famine being substituted in the early 1900s.