But I'd challenge you on your assumption that this is a bad thing for stores and consumers.
It's a powerfully negative experience to buy something, and then find out within a few days (or hours) that it's selling for far less. It happens millions of times per day (www.forbes.com/sites/walterloeb/2014/11/20/amazons-pricing-strategy-makes-life-miserable-for-the-competition/), and most people don't find out. But the reality is that it's happening.
A customer could return it for free (and re-buy it -- many states require this by-law). Or a store could do good by the customer and give a price adjustment.
It turns out that when stores do good by customers when this happens, shoppers become far more loyal (and spend FAR more on average too, growing store top-line & often net bottom line). This is part of the secret of Amazon Prime.
While I can't claim that it is the right or only view, I fully believe that stores will benefit far more than the costs.
*Revised based on mquander's feedback