buy something at the cost/expense/price of somethingto get something that you want, but only by losing something else 牺牲某事物去换取某事物 The town has been careful not to buy prosperity at the expense of its character. 这座小镇一直很注意不拿自己的特色作代价来换取繁荣。
→ buy something at the cost/expense/price of something at buy1(2)