"bupkes" (also spelled bubkis, bupkis and bubkes, I didn't find any dictionaries that spelled it "bupkus",like you did, but that means bupkes) is a Yiddish word meaning "beans." For a long time beans have been considered objects of little value, so bupkis means "nothing." Bupkes is often used in the sense of "you got nothing when you should have gotten at least something if there were any justice at all in this world. " Or as people around here,who tok reglar tok 'stead of Yiddish tok,sez, "Shoot far, Wilber Dean, I done spent months rustlin' and sellin these yere cattle and I din't git beans fur 'em." Even worse than bupkes is "bupkes on bupkes." Because of the influence of Yiddish on New York and of NY on theater and Yiddish Theater on General Theater, bupkes became a widely used term in showbiz, and thus on society in general.