Fast, easy money for the proles usually comes in some sort of illegal fashion, like selling drugs.

There was a Freakonomics article from way back that posited "Why do so many drug dealers still live with their parents?" And the answer amounted to street dealing being a really terrible way to make money. Your risks are high, because you're carrying all this illegal inventory and cash. Your sales are irregular, as your clientele's own income and consumption habits can vary heavily. And wholesale costs swing wildly.

The real money tends to be with the wholesalers and regional bosses, who manage the intercity trafficking and employ agents to distribute and retail sales. They take a sizable cut of revenue and can claim another cut as loan-sharks to their employees. They're able to launder their money into legitimate enterprise (Crooked Ladder: Gangsters, Ethnicity, and the American Dream also does a great job of documenting other historical instances of this post-Prohibition Era capitalization of minority circles) rather than living hand-to-mouth on criminalized incomes.

Street level drug sales are neither fast nor easy. Not since the Reagan Era War on Drugs really kicked into high gear, anyway.