Use the adjective extortionate when you're describing something that costs an outrageous amount of money, like extortionate parking tickets or an extortionate bill from your plumber.
Is the cost of something far beyond what's reasonable? Then it's extortionate! This word, with its sense of exaggeration, is a great way to describe prices that shock you. It comes from extortion, the use of threats or physical force to get something (usually money) from someone. So even if no literal extortion is going on, you may still want to wield this powerful word: "That theater may be fancy, with those reclining seats, but ticket prices are extortionate!"