The idea that anyone would go into folk music because it pays is bizarre, even insane. Traditional music was always 'of the people'; it needed nor desired marketing, had no agents or producers - anyone can stand up and sing a folk song.

To find a market that pays requires the performer to cross-over into popular culture. Usually that means they have sex appeal, or some other instant claim on attention, like a thoroughly remarkable voice. Marketing alone will not guarantee commercial success, nor will competence, even genius on an instrument (though it all helps). If you want to pay the bills, folk music is the last medium I'd choose to do it, and if you achieved it folkies would abandon you virtually to a man or woman.