As she is getting on the tractor, Lisa says "I'll see you in Burbank, Luther" a reference to the famous pioneer in agricultural science, Luther Burbank.
Newt Kiley sold his tractor three years earlier to buy a barking pig.
Adjusted for inflation, the $4,000 price of the tractor would equal approximately $37,000 in the year 2023. The $150/week salary for Ralph and Alf would equal approximately $1,400/week. The $980 price of Mr. Drucker's goods would equal approximately $9,000.
At the beginning when Lisa is collecting the eggs, only her hands are shown and her nails are painted a coral color. But seconds later when she's talking to Oliver in the living room, her nails are clear. Most likely someone else collected the eggs.
Lisa spends $4000 on a new tractor and $980 on farming supplies at Drucker's store, and hires the Monroe brothers as houseboy and cook for $150 a week.