costs an arm and a leg- 很昂贵
A: Hey mister! How much is that LV bag?
B: It's very cheap madam! It's only 90,000 RMB.
A: What! In Chinese there's a phrase, “你不如去抢钱算了”
B: What does that mean?
A: It means that your bag can cost me an arm and a leg.
B: It's Louis Vutton,maybe you can try H&M.