Tony Soprano decided that Jennifer needed to be whacked. He entered into a contract with Christopher under the terms of which Christopher was to do the job for twenty grand. To show his good faith, Mr. Soprano gave Christopher five grand at the time he ordered the hit. If Christopher performed the contract, and Tony failed to make any further payments, how much is Christopher entitled to?

The first step in our analysis is to determine the loss in the value to him of the other party's performance caused by its failure or deficiency, which we'll just call the "loss in value."

The contract called for Tony to pay $25,000. All Christopher got was a lousy five grand. What is Christopher's "loss in value?"