king's ransom

[king's ransom] {n. phr.} 1. An excessively large sum of moneyextorted by kidnappers to let someone go free.

The Smith family hadto pay a kings ransom for the freedom of their seven-year-old son,Tommy.

2. An exorbitant fee one is forced to pay.

The realtorsexacted a king's ransom for that choice lot on the comer.