A good negotiator listens for priorities hidden inside numbers.

Numbers are usually a summary of something else. A price that will not move may really be about a boss, a precedent, a fear of looking foolish; a demand for speed may be about a commitment made elsewhere. Listening to what the number is protecting tells you what can actually be traded. The figure is the surface of a priority.

When a number seems immovable, ask what makes that particular level important. Then look for a way to satisfy the reason without meeting the number. That is where most of the room in a negotiation turns out to be.