I can almost understand the value for the chia pudding thing that still lack a variety of off-brands. But haagen daaz, toblerone, et al are just the same regular product today (sometimes even lower quality than the local small brand of icecream/chocolate for example) with a markup because of the brand, somewhat justified because the brand evokes attention to quality (e.g. no expired product on display) and probably pays for better placement (e.g. top shelf or a dedicated store). Now you have the so-so product from the name-brand, with the markup removed because you removed the quality and placement! Is marketing for those brands alone that good?
It's not about brand marketing - it's about having cheaper options. I don't know where you go shopping, but at those prices I just listed, those name brand products are still cheaper than comparable products, local or otherwise.
It's not just removing the markup - they're usually priced at a discount relative to competitors. Also, in my area (SF), local products tend to be priced at a premium relative to standard rates for national brands. So for the ice cream example, the local pint normally would range anywhere from 5-10 dollars, whereas buying a pint of Haagen Dazs would run you about 4 bucks. Now, when I go to grocery outlet to pick up a two dollar pint of ice cream, I'm not buying the pint because it's brand name product for cheap relative to its normal cost - it's cheap relative to the cost of any ice cream. There's no comparable product at two dollars a pint.
I think you should try Grocery Outlet if its in your area, because this isn't really accurate, or at least isn't why people frequent it. There are usually unexpected products which are much (much!) cheaper than their generic alternatives, so it's often actually the cheapest option.
I can almost understand the value for the chia pudding thing that still lack a variety of off-brands. But haagen daaz, toblerone, et al are just the same regular product today (sometimes even lower quality than the local small brand of icecream/chocolate for example) with a markup because of the brand, somewhat justified because the brand evokes attention to quality (e.g. no expired product on display) and probably pays for better placement (e.g. top shelf or a dedicated store). Now you have the so-so product from the name-brand, with the markup removed because you removed the quality and placement! Is marketing for those brands alone that good?