Rabbit, dogs are opportunistic carnivores... meaning they are carnivores who WILL consume plant matter and carrion, but not if meat is available. It's a last resort, and therefore, grains should not be a "staple" in any dog's diet.
TOTW is actually really inexpensive, for the quality! I've tried a couple bags, and both of my boys loved it, even Mr. Pickypants Gonzo. ; ) You are going to be feeding WAY less of it than Nutro. Probably half as much, so the price should balance out.