I'm going against the grain here. Did you talk to Mrs. C? It could be that she manipulated him into a cheap price by telling him she had a bunch of work she will need done soon. Just her saying that could have triggered him to cut her a cheap price. Maybe you should call Mrs. C. and have a talk with her. Explain that the young man that is doing the lot is someone close and that you don't appreciate her taking advantage of him. There's always two sides to the story.