How much does this necklace cost?
这条项链多少钱？

A: I want to buy a necklace for my girlfriend.
我想给我女朋友买一条项链。
B: Which one do you like?
你想要哪一条？
A: Please show me that one. How much does it cost?
请给我拿那条。多少钱？
B: It costs 400 dollars.
400美元。


02
How much are these?
这些总共多少钱？

A: Please show me some notebooks and a pen.
请给我拿些笔记本和一支钢笔。
B: Here you are, Anything else?
给您，还需要其他的吗？
A: No, thank you. How much are these, please?
没有了，谢谢。请问这些总共多少钱？
B: That will be 3.5 dollars.
共3.5美元。

其他表达法：
How much is it altogether?
What's the price?
How much are you asking for this?