Is there a reason you're using only grain-free?
I only ask because Fromm has a very good line of foods with a lot of variety, and I use both their grain-free and the line with grains in it, for my dogs. I know some dogs (and some breeds) do much better on grain-free, but food has come SO far from the days when the grains were corn and wheat, that I don't avoid grains for health reasons any longer. And I have one dog who has trouble keeping weight on, so he does better with grains in his food, actually.
Fromm also has a frequent-buyer program, which I believe they offer online and that my local independent pet store offers: buy 12 bags and the 13th bag is free. The free bag is of the size you bought most frequently, which they track by saving the UPC codes from the bags when you check out. It's nice, every now and then, to be told 'you get a free one' and to add a bag to my order without adding to my bill.