Asking 'how much is the hotel for one night'

Question

I'm trying to ask "How much is the hotel for one night?"

After doing some reading online, I've come to two answers. But I'm not sure which one is correct.

このホテルは　いっぱく　いくら　ですか。

and

このホテルは　いっぱくが　いくら　ですか。

Is the が needed?

Answer 1

That が is not needed. いっぱくいくら is an example of the "X per Y" pattern which does not require が. You can also say:

• このホテルは いっぱくで いくら ですか？
  _{(で marks a "condition")}
• このホテルは いっぱくにつき いくら ですか？
  _{(～につき explicitly means "per ～")}

Using が may be not be entirely wrong, but I feel it's less natural than the other options.