There's a saying in Japan: ただより高いものはない (romanization: 'tada yori takai mono ha nai'). A literal translation of that might be: "there's nothing more expensive than free stuff". At face value, that seems like a non sequitur. Free stuff is supposed to be free, but the implication here is that it's not. This is probably why the saying gets more commonly equated to the old American adage: "there's no such thing as free lunch".