Hrm. I was checking out all of the brands comparable to Nutro, and they really aren't much cheaper. Authority MIGHT be cheaper by about $0.25 per lb, but with all of that corn, you're going to need to feed more so it should even out.

I definitely suggest buying the biggest bags, because it is a lot cheaper by the lb the more food you buy. Get large, air-tight tupperware containers for like $5 from Wal*Mart and store the food in there. You can also add veggies and meats (that won't flare up Kodie's allergies) so that you don't need to feed as much kibble... and, the added foods are good for them! You can add canned green beans instead of a portion of kibble, which are really cheap, into their food and it'll also keep them at optimum weight. Buy from Petco if you can, because if you buy 10 bags of Nutro over time, you get one bag free. Ordering online from Pet food specialty websites can also save money.