Cheap buy?

The other day, I was walking home from Bedok Interchange. I passed by this fruit stall and the uncle shouted something which sounded real funny.

He was trying hard to sell his fruits and he shouted "Cheap buy!" repeatedly. It sounded like some hokkien vulgar language! He sounded like he was scolding someone when in fact, he's selling his stuff.

Certain words just do not go well with each other.