This is a Comedy Trope where a character or characters try to buy some item (which is normally at least somewhat expensive), and tries to do so with nothing more than a few pennies of spare change, or lint, or some sort of ineffectual barter. Usually this trope is invoked just after the seller has told the character all he has to offer, all the options and all the flexibility in deal making. Either out of desperation or out of a literal interpretation of the idea of making a deal, the character then makes his own pitch, almost ALWAYS starting with the phrase, "What can I get for..."