Tinowantsto renovate the bathroom and kitchen in his home, and he hires Michelle. They enter into a contract after agreeing to a cost of $50,000. However, once Michelle starts work, she realizes that it will cost $25,000 extra to complete the work that she promised. To show good faith to Tino, Michelle tells him that she will split the added cost with Tino and asks Tino for an additional $12,500. Tino refuses to pay the additional $12,500, and Michelle threatens to stop work on the renovation.

After fearing that another contractor will probably charge much more, Tino agrees to pay the additional $12,000. After the renovations are completed, Tino refuses to pay the extra $12,000. Michelle sues Tino. Who wins? Please explain.