Person does not want you to see where the puppies are currently living. Puppies are dirty, lethargic, appear sickly, or have discharge from the nose and eyes. Person encourages you to take home a puppy younger than 7 weeks old. Person tries to tell you that AKC papers mean that the dog is of exceptional quality or exceptionally healthy. AKC papers simply mean that the puppy is registered as a specific breed because both of its parents were registered as that breed.
Papers are no indication of health , temperament or quality of a dog.
Person selling the puppy takes charge cards, is having a 'sale', or uses high pressure sales tactics to make a sale. Person offers you a puppy at one price with 'papers' and at a reduced price without. Person selling the puppy does nothing with their dogs other than breed them. They do not train their dogs. They do not participate in any type of conformation, obedience, field, tracking, working or agility events.