Todd agrees to repaint Jim's truck. The contract price is $2000. After preparing the truck for the paint job, Todd discovers an extraordinary amount of rust on the truck. He talks to Jim and explains that this level of rust is highly unusual for a truck of this age. Todd offers to get special equipment to remove the rust, but says it will cost him more money, so that he will be unable to complete the project for the agreed price. Because Jim is anxious to have the truck repainted, he agrees to pay Todd an additional $1000 to complete the job. However, once the truck is repainted, he changes his mind and now says he will pay only the originally agreed-upon amount. How much, if any, is Jim obligated to pay? Explain.