sunk cost fallacy
noun [ S ]
ECONOMICS, MANAGEMENT ukusthe idea that a company or organization is more likely to continue with a project if they have already invested a lot of money, time, or effort in it, even when continuing is not the best thing to do:
Economists would point out that the sunk cost fallacy is irrational, and could be described as "throwing good money after bad".
See also
Concorde fallacy