So i ve played the game so many hours and i think the best way to make money is hunting , yeah just do the jess black mission and unlock her then with her the hunting stuff is super easy , unlock the perks by hunting and get the harvest master perk and thats it , do some hunting and sell them , in like 1 or 2 hours you could make a good amount of money , it really depends on what you hunt and make sure to use bow and arrows to hunt .