If you have a Tractor Supply, they sell their own brand called 4Health. I used to feed that to Cuddles when I first got here. Her breeder actually recommended it, and that's what they were feeding her there. It is decent for a low-cost kibble.
Walmart also has a brand called Pure Balance. I've also fed that to her, too, when she used to eat kibble.
Both 4Health and Pure Balance also sell formulas that are not grain-free, however, so you have to read the ingredients.
4Health: 4Health Dog Food | Review | Rating | Recalls
4lbs for $7.99, which comes out to $1.99. Bigger bags are cheaper per pound.
Dog Food & Treats Online or In Stores | For Life Out Here
Pure Balance: Pure Balance Dog Food | Review | Rating | Recalls
If you can afford something that's a little bit more expensive than those foods, then I would recommend Taste of the Wild. Tractor Supply is probably the cheapest place to buy it.
I believe ToTW was $11.50 for the 5 lb bag at my store when I used to buy it. That comes out to $2.30 per lb.
I don't know if that is still the price here for it, but I know they had the cheapest price for it.
All of the formulas of ToTW are grain-free.
Taste of the Wild: Taste of the Wild Dog Food | Review | Rating | Recalls
You might be able to find good deals on a website called Chewy, especially if you spend enough to get the free shipping. I usually get a lot of stuff on there for cheaper than it is in the store. But the shipping is $5, unless you spend over $49.