Green’s Dictionary of Slang

not worth a plugged nickel phr.

also ...a lead nickel, ...a plugged dime, ...a (plug) nickel

(US) valueless; occas. used without not with the same meaning (see cit. 1912).

[US]Deseret Eve. News (UT) 4 June 2/1: Frank Hofman and Eddie Smith [...] made the old professionals look like thirty cents worth of plugged nickels.
[US]G.R. Chester Five Thousand an Hour Ch. v: Let’s look at these other blocks. The buildings on the one next to it are worth about a plugged nickel apiece.
[US]Day Book (Chicago) 6 Mar. 31/1: His life would not be worth a plugged nickel.
[US]P. & T. Casey Gay-cat 233: Wait till some o’ the kid mobs [...] hear tell o’ this, Frisco Kid. Yer life won’t be worth a nickel.
[US]H.C. Witwer Fighting Blood 83: The way business has fell off that he’s about ready to sell the joint for a plugged nickel.
[US]W.R. Burnett Little Caesar (1932) 137: If he failed, Scabby’s life and his own wouldn’t be worth a plugged dime.
[US]‘Armitage Traill’ Scarface Ch. i: If you stand me up again, your life won’t be worth a lead nickel.
[UK] (ref. to 1920s) L. Duncan Over the Wall 62: If you did squeal, your life wouldn’t be worth a plugged nickel.
[US]R. Chandler Little Sister 207: I’m not worth a plugged nickel to anybody.
[US]G. Cuomo Among Thieves 340: A man like me wasn’t worth a plug nickel.
[US](con. 1916) G. Swarthout Tin Lizzie Troop (1978) 25: That a man’s life on that side of the river wasn’t worth a plugged nickel?
[US](con. 1954) ‘Jack Tunney’ Tomato Can Comeback [ebook] The sleep I got for the next few nights wasn’t worth a plugged nickel.