Eight Is Enough (1977)

S3E5 Milk and Sympathy

Nicholas is infatuated with his teacher and decides to buy her self-portrait at her yard sale, but he keeps it a secret from his classmates, who suspect there’s a priceless artwork hidden beneath it. The Bradfords start to believe that Nicholas's painting could be incredibly valuable, leading them to fantasize about how they would spend their newfound wealth. Meanwhile, Tommy's opportunity to impress a popular girl takes a hit when he ends up with trench mouth.