"cost you an arm and a leg" and "for a song" don't seem like the others. Those two makes metaphorical sense without being idioms (even though they are idioms).

"cost you an arm and a leg" and "for a song" don't seem like the others. Those two makes metaphorical sense without being idioms (even though they are idioms). You could translate them to any language, dialect, etc. and the meaning is still clear. Not so with your other examples.