Sharon owned a 1989 Corvette, which she decided to sell to Steve for $20,000. As part of the deal, Sharon agreed to have the car restored for Steve. Sharon asked Rick, a vintage car restorer, to carry out the work within eight weeks for $4,000. A few weeks later, Sharon became worried that Rick would not meet the deadline and, eventually offered him an extra $1,000 if the restoration was completed on time. Steve was anxious to have the car on time as he was going to turn around and sell it to a purchaser he had already secured. Steve knew Rick was doing the restoration and offered to give him $500 for doing the work. Rick completed the restoration on time but Sharon refused to pay him the extra $1,000, arguing that Rick was already obliged to complete the work for $4,000. Furthermore, Steve told Rick that he can only give him $100, which Rick has reluctantly agreed to accept. Can Rick insist on the full payments promised by Sharon and Steve?