In case you've somehow managed to miss it you might also be interested in SPN RPS AU Fic: Maybe This (Jared/Jensen, Jared/Chris) NC-17 http://nu-breed.livejournal.com/58377.html which does do a lot with the issues of having a relationship.

Also of possible interest is Keiko Kirin's "Warmth" wherein Daniel briefly contemplates turning to prostitution to pay his bills but decides not to. http://pteropus.com/keiko/sg/warmth.html