I can't even fathom what you have in mind as "the ultra processed version of butter". Margarine is a completely different product from a different source.
Bread is a relative luxury regardless. The sponge-foam "wonder" stuff isn't even the cheapest for sale here generally. But even then, typical bread is (adding up the macros) only about 60% actual grain by weight (the rest mostly water), going by the nutrition label; so a kilogram of whole grain whatever equates to nearly two and a half loaves. Even whole rolled oats are much less expensive, on this basis, than the cheapest bread I can find and it's not complicated to cook them.
At any rate, bread and butter are two of the worst possible examples to make a claim about energy density in "healthy" versus "processed" options. Grain is grain (overwhelmingly carbohydrate and almost no water beside what is added in cooking or baking) and fat is fat.
Whatever it is you are trying to argue in your comment, it has nothing to do with the cost comparison I am making.
A kilogram of rolled oats can be easily found for about $3; white rice around $1.50 if you shop around; pasta from $1.33 to $2.22 depending (usually on the higher end of that); white flour $1 (in large bags).
A person can have a sandwich made of bread ate before your rolled oats are cooked. I think a huge portion of some people's confusion on why people eat what they eat need to look at time from picking the item from the panty to mouth to see that people spend a lot less time in the kitchen then they do.
I enjoy rolled oats uncooked in a bowl with milk and various berries sprinkled on top. Try it, for me they are more delicious uncooked!