LOL I am Level 25 now but not to worry as I'm after white buffalo meat and have been for 3 days. Unless KI does something about the drops it may be as high as I ever get. Oh to answer your question: I don't work (retired) and just plugged away at it.
Cool Ranch levels you up very fast. I first got here at level 19, Privateer. I am now half way through level 22 and I think I am mostly through with Cooper's Roost. Don't try the Scorpions until at least level 21. They are HARD!! and do only physical damage.