Well, anchoring works even when totally unreasonable. Never let the employer say the first number.

Another example of how the anchoring bias can influence monetary decisions is within salary negotiations. If you are negotiating a salary and your boss begins with an initial salary that is low after negotiating, you might be more likely to accept a lower salary than you would have if your boss had begun with a higher initial salary.

https://www.simplypsychology.org/what-is-the-anchoring-bias.html