Cheaper priced grocery stores tend to have less selection, and lower quality ingredients (not always, but a good fraction of the time). Grocery stores that are higher end tend to offer a wide variety of ingredients, as well as speciality items. Would you rather pay a little bit more and increase the quality of your ingredients?
I shop at both. There is a little privately-owned grocery store less than a mile from me. It has a much smaller selection but is pretty cheap. I run over there if I'm in a hurry or if I just need basics like bread, eggs, milk and what-have-you. I also sometimes shop there for all of my groceries when I'm on a really tight budget for the week. I shop for meat at Food Lion or Harris Teeter because it's of a higher quality. I also buy items there that I can't find at the cheaper grocery store. I guess you could say that I do about half of my shopping at the cheap, local store and the other half at either Food Lion or Harris Teeter.
It all depends on the season if the season is right for a fruit then there will be literally no difference at all. Seriously just because one store charges more does not make it better quality it is all a business. Having said that always buy fruit during it season.
I shop at Walmart. They are pretty much a hybrid of all retail stores. You can find just about anything you want at Walmart. i don't really have to make a choice between retail chains, because Walmart in a one stop warehouse.
I use both, too. I go to the cheaper store for all my basics.... flour, sugars, pastas, etc. I stick with mostly dry and canned goods from that store. And then I go to the higher quality store that sells name brand items at a higher price. I think by using both, I'm able to maximize my budget without compromising on quality too much.
I also shop at both and actually have kept my grocery budget very low for the last 5 years. The high end grocery stores put everything on sale on a cycle, so actually i find ridiculously good deals there (unbeatable, seriously) on almost everything. But I use Aldi for staples and for weekly stock ups because their baseline price on produce, bread, and dairy is always cheap and a great deal.
I don't mind paying more if the difference is not huge, because we all know that you get what you pay for, and I think if I were to choose then I would choose the product with the better quality over the inferior one. I have always shopped at the large grocery stores though.
I usually shop at both, depending on what I am craving or what I need. More often, however, I just shop in the mid range groceries that pretty much have both the cheaper products and the higher end ones. I'd sometimes still need to venture and seek out the really cheap groceries, though, since I do still like finding the cheapest prices for some of the products and if they are cheaper somewhere else, then there really is not much reason for me to pay a higher price for them just because the venue is a little more comfortable to shop in.
I like to mix up my groceries with both cheaper and higher-end grocery stores. If it's something basic that I know will taste the same either way and the quality won't be affected, than I'll purchase it at a cheaper store. But for things like meat, produce, etc - I'd rather shop higher end. I just feel like the quality is better as well as the taste. However, I try to eat as cheaply yet as healthy as I can.