Judas of Kerioth [Iuda iz Kiriafa]
Bulgakov's choice of the Russian explanatory place name here would remind readers of the traditional Biblical name: iz Kiriafa / Iskariot.
Judas's payment in Matthew 26:15, "Thirty pieces of silver," was a relatively small sum, but it derived from an obscure passage in Zechariah 11:12-13, which is also the source for Judas throwing down the money in the temple.
Silver shekels of the 1st Century
Bulgakov has "thirty tetradrachmas." A tetradrachma is a silver coin worth 4 drachmas.
A silver tetradrachm of the 2nd Century