Barbie hires Ken, a flooring contractor, to install carpet in her guest room. Ken gathers measurements and dimensions of the size needed to order from the factory and provides a quote (valid for 30 days) to Barbie, who agrees and signs. He then orders the carpet from his supplier and is told it will be delivered in 2 weeks. He emails Barbie the lead time and updates with the order confirmation, and she is unhappy because her sister, Chelsea, is visiting in 1 week, but proceeds. The supplier is running late and doesn't deliver to Ken until 3 weeks later, who then immediately goes to Barbie's house to install and complete the work, only to find Barbie has hired someone else and had the installation completed already, and no longer needs his services.

Who breached the contract? Can Ken still enforce or have her pay for materials? Can Ken then turn around to the supplier and go after them for causing him to lose the job, and ruin his chances with Barbie? You must provide a source for the law or laws that support your conclusion. Please also provide the necessary elements to form a legally binding contract in your answer.