What is An Arm And A Leg?
1.
Figuratively, what one would have to sell or otherwise place as collateral in order to afford something of great expense.
Comes from the fact that, when buying things of great expense, it actually feels as if you are having to offer said appendages as collateral for said item you are purchasing.
Man, I just had to spend an arm and a leg to get my car repaired.
2.
an outrageously high price, en excessive price
Don't pay an arm and a leg for your internet service, switch to -* insert company name here *- today.
See
3.
A large amount of money; very expensive or costly.
Some things are so expensive that they are painful to buy, and cost everything you have.
My new Mercedes cost me an arm and a leg!