I remember a story (someone told me it was in Mexico), very similar. A guy was printing $20 pesos bills but only when he needed some extra money. He had, IIRC

I remember a story (someone told me it was in Mexico), very similar. A guy was printing $20 pesos bills but only when he needed some extra money. He had, IIRC a print shop, and since he was humble enough, he never raised suspicion. So I guess the key to profit from counterfeit money is to just print a small amount here and there.