What happens to the price and the number of goods and services sold when a store runs a sale? How do these factors relate to the downward -sloping curve?

Suppose that a candy maker owns a building and is renting part of the building's space to a doctor. further suppose that because the candy maker is the owner, he has the right to make noise during the day while he makes candy. while the doctor cannot insist on a quiet environment, the doctor could move to a quieter building. however, rent in the next best building is $350/month more than rent in the noisy building. the candy maker can adopt a new technology that eliminates the noise for $275/month. given this situation, can the doctor find a private solution with the candy maker that will make both better off?