I'm having a hard time phrasing my question into words, so I'll provide an example:
Imagine you ask someone how much it'll take to eat a worm. The person says they would eat a worm for \$20. Instead of offering \$20, you offer 1 dollar less. Reluctantly, they say yes to \$19. You proceed to offer 1 dollar less so on and so forth. Eventually the reward money draws close to \$0 and we're left with a bizarre situation.
Is there a name for this phenomenon or am I totally bananas?