Son's Backrub Emporium

As the lemonade stand business tends to dry up somewhat in the cold season (and who wants to sit in the front yard in sub zero temps anyway), Son decided to go into a new off-season business. He sells backrubs. As his first customer, I was treated to the following observations, during a ten minute backrub:

• I think ten cents a minute is a good rate, don't you? Because then ten minutes is a dollar. Boy, if I go for an hour, I can make it big time! Wait; it's only six dollars. Hey, but still, that adds up fast, doesn't it Mom?
• My hours are: after my homework is done, until seven or eight o'clock. Tonight I'm workin' late. But only for tonight.
• Sometimes, I give free backrubs. Samples. But samples are only three minutes long.
• I want to open a spa, too. But I'll have to use the bathtub if that's okay. Because I don't have my own hot tub or anything.
• You have three minutes left.
• You're at time. You should know that it's still ten cents a minute. Do you want me to rub your back some more? For ten cents a minute? Mom?
• Thank you for being a customer. You'll find me here tomorrow, too. After my homework is done.