When I was a little girl, I loved Sprite soda. I loved the green bottle it came in, I loved its lemon-lime flavor, I loved the carbonation.
I couldn't believe how little it cost --- it was something I could afford even on my little allowance. I remember asking my dad how stores could afford to put even my beloved Sprite on sale, when it was so low-priced in the first place.
He pointed out to me that the cost of a bottle of Sprite is mostly the cost of the bottle itself. I didn't know that packaging was the major part of the price tag for food & drink items. My eyes were opened.
That's why the bulk food section of the grocery store is a great place for value. It's not always necessarily the lowest price (compared to weekly specials), but a majority of the time it is true, and it's extremely easy to verify.
For example, Quaker Oats is promotionally-priced this week at $2.50 for 42 oz, or 95 cents a pound. The everyday low price of oatmeal in the bulk food aisle is 75 cents a pound. We eat a lot of oatmeal in my house, so that 20 cents savings adds up, and that's a savings of twenty cents per pound based on the This-week-I'm-on-sale price, because usually it costs more.
From the eco-conscious perspective, I don't purchase the flimsy cardboard Quaker Oats container (back in the day, it was sturdy enough to repurpose) only to throw it away each month once the oats are gone. I keep my oats in a refillable & handsome mason jar.
At my local grocery stores, they literally have the same products in the bulk bins as the ones sitting on the shelves: flour, pancake mix, sugar.
Between the cornmeal, lentils, rice, dried cranberries, and almonds, I have a lot of mason jars in my cabinets.