Leftmost digit bias: humans have a heuristic where they look most closely at the leftmost digit. This is why most infomercial products are priced $19.95 instead of $21 or something. Furthermore, each additional 10k mark increase in car mileage, price drops significantly.
Last Objection: A salesperson asks about a clients last objection. They then resolve the objection and ask the person to uphold their promise that that was their last objection.
Testimonials: people understand a story better than just data. Giving actual examples will help close more deals.
Love Bombing: Cults bring in new members and get them to commit by “love bombing” them… basically being extremely warm and open and accepting that the person is there.