可以直接问：

What price can you offer?

Could you please tell me your target price?

直译的话可以说：

This is not the final price. 后面可以加上 It depends on ... 来作为讨价还价的条件，不能一下子就让步对吧？

We can have a further discussion on the price.

The price is negotiable.

总之，我觉得第一不要太生硬，第二不要轻易松口，给双方都留点后路。