高くはない conjugation

[7daytrial]

I've recently come across: 高くはない

and it seems like it has the same meaning as 高くない

Does anyone know why は is added?

[hatch_jp]

In this case, "は" is used to show contrast、I think.
I'm not sure coz I don't get the previous or following sentence.
Furthermore, I'm not sure whether 高い means high or expensive.

高くはない（でも、安くもない）
It is not expensive (, but not inexpensive)

Otherwise, は is used to emphasize the subject.

[7daytrial]

The conversation was about a popular onsen. I don't much about them so I asked if it was expensive and the reply was:

温泉は日帰りならば高くはないですよ！

So I guess in this case は is used to show contrast between 'a day trip at the onsen' versus a longer stay.

[Elfunko]

LOL, you heard that in the onsen didn't you...