可不便宜

not cheap at all

→ 可
phrase Rare #26,163
not cheap at all 可 adds emphasis; the phrase often implies that something is quite expensive.
CH: 这家餐厅的菜可不便宜。
EN: The food at this restaurant is not cheap at all.

要请我可不便宜

Hiring me doesn’t come cheap.

— 荒野大镖客 (1964)

不过,建造你的第二艘货船可不便宜;去年,这多少泄露了你手头有多少钱。

However, building your second cargo ship wasn’t cheap; last year, that gave away roughly how much money you had.

这个汤可不便宜呀

This soup isn’t cheap.

— Deep Sea (2023)

不过我收费可不便宜

But I don't come cheap.

— 维多利亚 (2015)