The other difference with Amazon is that they have very low quality enforcement, and offer counterfeit items. So "Amazon Basics" is a strong indicator of quality for commodities and they can charge as much or more than for brand name items.

A Safeway house brand is usually offered at a small discount to the name brand, because the consumer trusts the name brand more.

Yep. If I need a USB cable or some other electronics commodity, I at least know that the Amazon Basics isn't a knock-off and it's at least good enough. That, of course, reflects badly on Amazon in other ways but it is, as you say different from store brands which are mostly about undercutting perceived premium brands with good enough product for people who aren't fussy. (Or for offering a cheaper alternative for things that really are commodities.)

Now that we have ubiquitous Internet access, I think it's important to reinforce the point that you shouldn't use a store - whether a brick&mortar or on-line - as a product discovery and recommendation engine. You won't find the best value for money this way.

Then what do you recommend?