You go to an online store to buy a hard drive. It's listed as "in stock" and you buy it and pay for it. A week later you get an email from the store that the specific hard drive is now available at a third party warehouse and they can order it from there, but the price is about 10% higher.
The above actually happened to me. That's what online retailers were like before Amazon's reach properly extended here. That's also the main value proposition for these retailers for me.
Also, online retailers are far more likely to accept returns compared to regular stores. If you get a bad product from a regular store you're often just screwed.
The late-Amazon process for this is to just send you whatever's marked as the hard drive in their warehouse, which may be that actual product, a counterfeit, or a brick in the hard drive's package.
Later, when you want to try the return, a black box algorithm asseses your transactional value to Amazon and decides whether your concerns are worth attending and to what degree.
Maybe that really is better than whatever you were used to in your own market, but it's a profound regression on the traditional retail experience for most of us here.