The first number you see secretly anchors every price you judge afterward

In a classic experiment, people spun a rigged wheel that landed on either 10 or 65, then guessed what percentage of UN countries were African. Those who saw 65 guessed far higher than those who saw 10, even though the wheel was obviously random. Any number you're exposed to first quietly pulls your later estimates toward it.

— Amos Tversky and Daniel Kahneman, Judgment under Uncertainty: Heuristics and Biases — Science, 1974