I like the idiom
IT COST AN ARM AND A LEG
it is used to describe something that is very expensive .
`The new fancy sports car cost him an arm and a leg
No on is exactly sure where the idiom came from. One suggestion is that is relates to the world wars where the soldiers did loose limbs so the cost of the war was high.*
There are some indications that it could be older than that as well
I´d love to hear you favorite English Idiom:)
Feel free to message me with your favorite Idiom:) I love to hear from my students :)