Mr. Pink is the only one not to tip, and everyone else, people who are about to rob a liquor store, potentially kill people, mostly unlikeable except for Mr. Orange, who stays out of the argument, lecture him about it. Mr. Pink is pragmatism personified.
shareNotice how Orange rats out Pink as the guy who didn't "throw in a buck".
Also, Blonde is seen as both, a psycho and loyal to Joe ("Hey Joe, you want me to shoot this guy?")
Nice foreshadowing all around.
Life redirected in ways unexpected, Sometimes the odd number wins
Not a liquor store - diamonds. Orange does not stay out of the argument, after saying it was Pink who didn't throw in, he says, "He convinced me. Give me my dollar back." There is other foreshadowing - White is bothered about the economic condition of waitresses, which foreshadows his altruism towards Orange later in the film. (In an original draft of the script it was White who wouldn't tip.)
"Chicken soup - with a *beep* straw."