3D printer produced a gun for only $35

As I have warned in past posts, one uses one of these plastic guns at one's own peril.  But the cost of these guns is amazingly low.  From the Sydney Morning Herald:

The gun only costs $35 to make on a 3D printer, with instructions downloaded from the internet. 

NSW Police Commissioner Andrew Scipione said on Friday police easily made two Liberator plastic guns on a $1700 home 3D printer. From 16 parts it only took police 27 hours to build the guns. . . .

In order to function and keep the gun from exploding on you, two metal parts needed: a steel barrel and firing pin.  I don't know how much those parts will add to the price of this guns if they are made using a 3D printer that uses metal, but you would have to believe that it can't be that much.  In any case, Cody Wilson, the guy who put the original 3D gun together, used a metal nail for the firing pin.

UPDATE: Apparently, someone named "Joe" figured out how to make a cheaper gun and he apparently demonstrates that a generic Polylac PA-747 ABS fed is stronger than the more expensive ABS plastic and shows nine shots being fired (though the footage is interrupted).  This engineer figured out how to make the gun for only $25.