Do you have a Tractor Supply company in your area? I pay $45 for a 30 pound bag at TSC and that is the standard TSC price (same on their website). I pay just under $43 for a 30 pound bag of TOTW from my trainer.
Other good foods that are somewhat similar to TOTW (grain free) are Evo, Orijen, Wellness CORE, Blue Buffalo Wilderness, Nature's Variety Instinct, Artemis, Acana, Before Grain, Canidae Grain-Free, and Fromm.
Taste of the Wild is generally the cheapest grain-free dog food. I don't recommend switching a dog on a grain-free food back to grains unless it's absolutely necessary. I don't intend to feed a grain-containing dog food ever again. I had so many poop problems with Logan when he was on Diamond Naturals, and they cleared up immediately and completely when I switched him to TOTW. Gavroche gets even more skin issues than he already has when he's on a grain-heavy dog food.
Remember that you feed LESS of a nutrient-dense food like TOTW than you would of a cheaper, less-nutrient-dense food, so in the end it's usually the same price or even cheaper to feed the better food. Logan ate 5 cups a day of Diamond Naturals Chicken and Rice, and is eating just over 2 cups a day of TOTW. Gavroche ate 3 cups a day of Purina ONE, and now he's eating just under 2 cups a day of TOTW (he was at one point eating one cup a day). Logan is 72 pound and Gavroche is 53 pounds.