Charleswants to renovate the bathroom and kitchen in his home, and he hires Veronica to do the work. They enter into a contract after agreeing to a cost of $40,000. However, once Veronica starts work, she realizes that it will cost $15,000 extra to complete the work that she promised. To show good faith to Charles, Veronica tells him that she will split the added cost with Charles and asks Charles for an additional $7,500. Charles refuses to pay the additional $7,500, and Veronica threatens to stop work on the renovation.

After fearing that another contractor will probably charge much more, Charles calls Veronica and tells her he'll pay the additional $7,500. After the renovations are completed, Charles refuses to pay the additional $7,500, despite agreeing to it. Veronica sues Charles. Who wins? Please explain.