It is a slang expression that has a general and particular meaning.
The general meaning is knowing if something is worth the trouble of trying to get it, i.e. does the reward outweigh the punishment.
"I'd rob a bank if I could, the juice is worth the squeeze."
A particular meaning refers to not stealing one's girl unless one is ready to accept the consequences.The juice refers to the girl in this case.
Example:
A: Dance with her!
B : I don't know about that. Her boyfriend is tough looking.
A : Man, I'd do it if I had the chance.
B : Yeah, you're right. The juice is worth the squeeze.