kings ransom
king's ransom  {n. phr.}
1. An excessively large sum of money extorted by kidnappers to let someone go free. 
The Smith family had to pay a kings ransom for the freedom of their seven-year-old son, Tommy.
2. An exorbitant fee one is forced to pay. 
The realtors exacted a king's ransom for that choice lot on the comer.
Categories: 
 
Source: A Dictionary of American Idioms
