THEM: would like the book and 1 hat. you can have the rest.  YOU: how about you take both balls and i get the rest  THEM: no the balls are worthless to me. i need the book and 1 hat.  YOU: how about you just take the book only  THEM: no i need the book and at least 1 hat.  YOU: i also need the book and one hat  THEM: make me another offer.  YOU: i can offer you the book and both balls  THEM: okay i will take the book and both balls.