The cost of this English book is three hundred dollars.
這本英文書的價錢是三百元。
What is the total cost of our class trip?
我們班遊的總費用是多少？
The cost of living in Taipei is quite high.
在台北的生活費用相當高。
My parents work hard to pay for our living costs.
我的父母努力工作來支付我們的生活開銷。