Probably information on expected pricing or price tolerance.

Overall, you can get many of these signals without needing to read their minds if you apply yourself. You can tell a great mixture of things based solely on, posture, facial expression, tone of voice, level of eye contact and the number of questions they are asking.

Never settle for a yes or no. Probe deeper by asking one or more follow up questions until you feel you've achieved the level of detail you needed.