In 1965 I first started feeding Purina, one dog,and until 2001 I continued to feed 2-3 bags per month to 5-7 dogs. When the difference in price was $13 per bag and I had analyzed the nutritional values between Black Gold (50#) and PPP( 37 1/2 #) I changed to Black Gold. Purina is a first class food and if a person's dogs are doing well on it , by all means stay on it. Money is important, but your dog's health is more important. The field reps for Purina are First Class- Bob West, Keith Schopp, Pat LaMancha, Roy Pelton, Dean Reinke all fun and good guys-a great group, a good dog food, acompany that has excellent marketing stratiges-tell them thank you and walk away.