It cost me an arm and a leg.
→그거 엄청 비쌌어.

[예문]

A: Hi Mike, how are you dealing with things?
    I heard you were having some medical tests.
A: 안녕 Mike, 요새 어떻게 지내냐? 네가 건강검진을 받는다고 들었어.

B: Yes, I was in the hospital. They were checking to see if I had skin cancer.
B: 맞아, 병원에 있었지. 내가 피부암이 있는지 확인했거든.

A: I see. What was the result?
A: 그렇군. 결과가 어떻게 나왔어?

B: I'm fine. But it cost me an arm and a leg. I had to pay 500 dollars.
B: 아무 문제없대. 하지만 검사비용이 엄청 비쌌어. 500 달러나 지불해야 했지.