How does the lowball technique of persuasion work?
An initially attractive offer is agreed to; the offer changes for the worse, the revised offer is still honored.
An initial offer is agreed to; the offer improves with additional benefits at no cost; the new offer is rejected.
Two initial offers are requested side-by-side, and the choice is to identify the one that is a trick.
An initial small request is honored, making it more likely that a later, larger request will also be honored.