Chaffer is a verb that means to haggle or bargain.
Coming from Middle English, our word of the day was in the past used as a noun that referred to ‘a bargain.’ These days it is mostly used as a verb that is a synonym of ‘haggle’ or ‘negotiate.’
Here on the west coast, I find that merchants are less open to having their customers haggle with them for a better price. Whereas in New York, we used to chaffer over the prices all the time.