Answer: 5 pounds
Alfred: "Just one good spree for meself and the missus, giving pleasure to ourselves and employment to others. And satisfaction to you to know it ain't been throwed away. You couldn't spend it better."
Prof. Higgins: "Oh, this is irresistible. Let's give him ten."
Alfred: "No. The missus wouldn't have the heart to spend ten, governor. Ten pounds is a lot of money. Makes a man feel prudent-like,
and then good-bye to happiness. No, you just give me what I ask, governor. Not a penny less, not a penny more."