[nagdu] possibly switching dog food, advice would be welcome

[Laurel and Stockard]

Hey all,
I don't post much, but occasionally, I need advice. I've got my guide, a female labrador in great health, on natural balance duck and potato along with my family's pet labrador, also in great health. My guide is 5 and a half and our pet is a little over 2. I've got to switch Stockard my guide as well as our pet dog off the natural balance because it's running 60 dollars a bag of late and I can't really afford that. I'd like to know what brands you use, and what you find affordable, like under $50. Keep in mind, my dogs are labradors. Specifically, I want your thoughts on a few brands. Eukanuba (especially whether or not I should think about large breed vs. labrador. Is one better than the other, does it matter?) also, royal canin, nutro, Kirkland from Costco, and Iams. Is there another brand that's affordable that I should consider? Are there any websites where I could order in bulk, say 5 or 10 bags at a time, and save money?
Thanks for your thoughts on this matter.
Laurel and Stockard