This is what I get:
Quaker Oats Old Fashioned Oats, 18 oz - Walmart.com
It's not even three dollars, 13 servings at 40 g per serving (that's about half a cup, which is too much for me.) That's two weeks worth of breakfast, maybe one week if you need a larger breakfast. Add berries for flavor and fruit intake, seven dollars for breakfast for a week.
Here's generic:
Great Value: Oven-Toasted Old Fashioned Oats, 42 Oz - Walmart.com
That is a fantastic buy, easily 30 servings of half a cup for three dollars. You'll save money the rest of the month by not needing to buy breakfast. That's $.10 per breakfast, before fruit.
These blueberries will last you for the week easy for another three dollars:
Great Value No Sugar Added Blueberries, 12 oz - Walmart.com