an arm and a leg（俚语）一大笔钱，昂贵的代价，经常与charge/cost/spend/pay等动词连用，表示收费贵/花费很多钱。

1. He’s a very good plastic surgeon. Plus, he’s fresh out of medical school, so he won’t charge you an arm and a leg like others usually do.
他是个非常出色的整形医生。而且他刚从医学院毕业，不会像其他老资格的同行那样收过高的费用。

2. You must have spent an arm and a leg!
你肯定是付出了昂贵的代价！

3. I’m sick of paying rent in this town because it costs an arm and a leg!
我讨厌在这个镇上付房租，因为太贵了!

4. These resort hotels charge an arm and a leg for a decent meal.
这些度假酒店吃顿像样的饭都要花很多钱。

5. This ring cost me an arm and a leg. I’m gonna pop the question to Mary. Wish me luck!
这个戒指花费了我很多钱。我要向玛丽求婚！ 祝我好运！

6. Fixing the car is going to cost an arm and a leg. Why don’t you buy a used car?
修车是要很多钱的。你为什么不买一辆二手车呢？

7. Hey, your new car is really worth an arm and a leg！
嘿，你的新车真的很值钱呐！