Choices and persuasion
Anchoring
Also called Anchoring bias, Anchoring effect
The first number people see pulls their later judgements towards it, even when it has nothing to do with the decision.
People adjust from a starting point, and they rarely adjust far enough. A high first price makes the next one look reasonable; a big first estimate makes later ones bigger.
In products, the order of plans, the first figure on a page and the default amount in a field all act as anchors. Put the number you want people to judge others by first, and make sure it's honest.
In practice
A pricing page that lists the team plan first makes the individual plan look affordable, where listing the cheapest first makes everything above it look expensive.
Common mistake
Inventing anchors: a 'was' price nobody ever paid, or a fake list price. It's misleading, and in many countries it's illegal.
Where it comes from
Demonstrated by Amos Tversky and Daniel Kahneman in Judgment under Uncertainty: Heuristics and Biases (1974), where a spin of a wheel of fortune changed people's estimates of how many African countries were in the United Nations.