Try not to eat so much processed food for starters. Food that is naturally gluten free is along the cheapest items in the store: beans, rice, produce.

Look for frozen fruits and veggies in bulk. Nuts and seeds and gluten free gains, too.

The cheapest nondairy milks I’ve found are always the shelf-stable versions, not the refrigerated ones. Depending on the price of cashews you can make cashew milk.

Look for many of these items in the cultural food sections or at discount stores. I was stocking up on garbanzos the other day and put back several cans when I found them a full ten cents cheaper a can in the “international” aisle (Goya brand) versus the Walmart brand in the bean and canned veggie aisle.