Same here. It stinks, doesn't it? I dont know about you, but i live in complete suburbia. Im talking 1/5 acre lots per houses. I dont keep my chickens at my house even. I keep them on a couple acres outside of town owned by someone else. For that reason, stores sell nothing but Purina and Dumor here. No good show rations.
Let me tell you what I do- Take a bag of Purina, Dumor, whatever. Put 25 lbs of it in a trash can. Then put 5 lbs of manna pro poultry conditioner. Thats 20%, which is the maximum recommended amount. Put in 2 cans of quaker oats, and about 5 lbs of black oil sunflower seeds. Mix it all up. You could even add dried, crushed marigold blossoms if you want.
For me, the above works amazingly. The purina is a good base that supplies most of their nutrition, the conditioner supplement is 22% protein, so works amazing for growing the birds into a nice brick shape. The oats and sunflower seeds work wonders for feather quality. Shiny, well nourished feathers. And, of course, marigolds for shank color.