cost someone dear idiom
UK让…花很多钱;使…损失一大笔钱
to cause someone to spend a lot of money or lose money
Buying that second-hand car without having it checked by a mechanic first cost us dear. 没先请机修工检查就买了那辆二手汽车，这让我们亏了许多钱。
UK使…付出沉重代价；使…饱尝苦头
to cause someone a lot of problems
Later that year he attacked a photographer, an incident that cost him dear. 那年底他攻击了一位摄影师，这件事让他付出了巨大代价。