Noun + 몇 없다
Let’s take a look at the pattern Noun + 몇 없다. 몇 is often used in questions to ask how much or how many. When used in a plain statement just like this one, it means a few or a couple of something. And since the verb that follows is 없다 which means to not have, it means that the noun before 몇 is are, not a lot, or not many. We use this to tell someone to value not take someone for granted as a person like that someone is rare to find.
그런 애들 몇 없다.
There aren't many guys like that.
그런 친구는 몇 없어요.
There aren’t many friends like that.
용재만큼 착한 남자는 몇 없거든.
Guys like Yongjae are rare to find.
현서처럼 예의 바른 애들은 몇 없다.
Girls are polite as Hyunseo are rare.
그런 엄마는 진짜 몇 없다니까.
I am telling there aren’t many moms like yours.