One of a series of secondary level teaching units presenting case studies with pro and con analysis of particular legal problems, the document presents a student's lesson plan, a teacher's lesson plan, and a lawyer's lesson plan on unconscionable clauses in sales contracts. The unit acquaints students with the operation of sales contracts and commercial transactions, while providing them with an appreciation for the significance of "freedom of contract." Although similar in content, student and teacher lesson plans are presented separately to facilitate independent and small group work by students and to provide additional background information for teachers. Prior to a lawyer's visit to the classroom, students examine hypothetical case studies to determine whether or not a contract exists in each case. Students then discuss a case study with a visiting lawyer, study a list of deceptive sales practices, and read the lyrics of a song entitled "Smiling Faces" (Whitfield & Strong) from the point of view of a consumer. In a final activity, students engage in a role play of a case concerned with sales contracts. Teacher materials include information about section 2-302 of the Uniform Commercial Code, a reading on court systems, and a simplified view of the federal and California court structures. The lawyer's lesson plan presents further questions and discussions concerning case studies, information about the Uniform Commercial Code, and additional hypothetical case studies. (LH)