Household vacuum cleaners question?

Up until the seventies they were sold with a lifetime guarantee. A Kirby vacuum in t 1972 sold for over $700. If you bought the complete Classic model ( floor polisher, rug shampooer, upholstery cleaner, knife sharpener, rodent sprayer and more... it was over $1100.. But they would sell them on payment plans that allowed anyone with a job to buy one.