What phrase is used to describe something very costly?

The phrase "will cost you an arm and a leg" is an idiomatic expression that vividly conveys the idea of something being very expensive. The imagery suggests that the price is so high that it equates to losing a significant part of oneself, emphasizing the cost involved. This expression is commonly used in everyday language to describe not just monetary expense, but also situations where the value required is extraordinary or potentially burdensome.

In contrast, the other phrases do not relate to costs or expenses. "Green around the gills" typically refers to someone looking ill or nauseous, "strenuous" describes something requiring great effort or exertion, and "drafted" relates to being selected for a specific purpose, often in a military context. Therefore, by understanding the meaning and context of these idioms, it's clear why the first option effectively captures the essence of something being very costly.