I raised meat chickens for human consumption this year, first time. Had them in chicken tractor which is just a moveable pen so they could eat grass and get exposed to sunlight. Meat chickens basically just eat and poop and grown. Meat chickens are also way smellies than laying hens because of the amount of poop they produce. Had 27 chickens and went through 5 or 6 100lb bags of feed. Dressed weight was about 2 lbs less than their live weight, though if you will be feeding your dogs then you may do a bit better if you keep the head, feet, and all the organs. It cost us $2.00 per chicken the have them processed, which included dispatching, dressing, and bagging. I know some raw feeders just feed the chicken whole, feathers and all, some grind, and some pluck and remove the digestive system and feed whole or grind. A grinder that can handle chicken bones will run you at least few hundred.
Now it is probably cheaper to just go buy chicken from the store on sale, but you will have no idea what all that chicken was fed, and most store chicken has added sodium as well. Home raised chickens also taste way better than store chicken unless you maybe buy organic or direct from some family run farm.
If all you have is a hammer, everything looks like a nail.