From Longman Dictionary of Contemporary Englishdickerdick‧er /ˈdɪkə $ -ər/ verb [intransitive] informal especially American English to argue about or discuss the details of a sale, agreement etcdicker about/over Politicians in Washington are still dickering over the budget.→ See Verb table
Examples from the Corpus
dicker• "The prices on the vehicles are the real prices. We don't dicker, " Olsen said.Origin dicker (1800-1900) Perhaps from dicker “group of ten (animal skins)” ((11-19 centuries)) (from the exchanging of skins for other goods) 