farb man
n.— «Farb man—same as switch man; When a customer goes in a rear room to obtain the article he has purchased, the farb man tries to sell a more expensive article.» —“Jewelry Auctioneers’ Jargon Obtained From Auctioneers and Jewelers on 42nd Street and 14th Street” by Hatch in New York City Lexicon of Trade Jargon , 1938-39. (source: Double-Tongued Dictionary)