Anchoring Bias

The tendency to rely too heavily on the first piece of information encountered when making decisions.

A job candidate is asked about their salary expectations. They mention $80,000, and all subsequent negotiations revolve around that figure, even though the role might have been budgeted for $100,000. The initial number anchored the negotiation, potentially costing the candidate thousands of dollars.
A store marks a jacket as "Originally $200, now $100." Shoppers perceive this as a great deal, even though the jacket was never actually sold at $200. The artificial high anchor makes the current price seem like a bargain.

Note

First documented by Amos Tversky and Daniel Kahneman in 1974 as part of their research on heuristics and biases.

This is a common bias