I've always butchered my own game including grinding it and making my own sausage. I was taught to do so by my grandfathers and father. I've never looked at a video or read a book on it, I just do it the way I was taught. When you kill, cut, grind and wrap game yourself you have total control of the entire process. When you pay someone to do it you lose that control.

Plus, I feel you owe it to the animal you killed to do the job yourself rather than pass it off to a paid flunky.