Doc Ernie's Inventions is a vendor on the Liberator in Russia, run by Benny. It trades in experience. Unlocks after Doc Ernie gives you his suppressed Bluntforce (he offers it once you have finished 4 quests that count toward promotion).Complex blueprints for complex creations.
Bayonet BlueprintCosts 170 experience · Unlocks after Doc Ernie gives you his Bayonet Blueprint (he offers it once you have finished 7 quests that count toward promotion and took his Bluntforce)
Quadbarrel BlueprintCosts 190 experience · Unlocks after Doc Ernie gives you his Quadbarrel Blueprint (he offers it once you have finished 16 quests that count toward promotion and took his Bluntforce, Bayonet Blueprint and Ace)