There are some sellers who "prefer" certain things, such as only drugs or bullets. There are salespeople who work only with certain types of buyer - charismatic and charming people, or small-guns-skilled tough guys.
It would be logical to assume that there must be traders who prefer to deal with the goods, which is obtained by theft, robbery, extortion, fraud or crime. And who prefer to deal with customers with the skills to theft or burglary.
Perhaps this hypothetical seller would also serve the players, not formally have stained their hands with blood and offenses against property, personality and humanity. But the price in this case should be not only the money earned by a hard honest work, but fall's reputation in the eyes of the adherents of the rule of law, the guardians of morality and ethics.
Fence - that's the character that its gloomy appearance should emphasize the unique feature of the world's Fallout, which offers players a completely different methods for self-actualization.