I hate to be a 'naysayer',
Red but "sticking it to the manufacturers" is not entirely accurate, or at least not in the way you seem to envisage.
A great many of the 'cheap' products sold by such establishments (as I said, Wal-Mart is not alone, just one of the worst) are manufactured outside the USA under conditions that would be illegal in your country.
Who actually suffers from this particularly nihilistic brand of 'free market piracy' are our counterparts in other countries i.e. poor working stiffs whose existences are no different from that of slave labourers.
It is true that by using the enormous lever of their fiscal size, the likes of Wal-Mart can secure lower prices for the consumers they choose to do so for but, as I noted in my post above, this is a short-term gain only.
If they eliminate all the competition in their locality then prices will soon go back up again - the much vaunted 'free market' does not charge what is
fair but what the market will
bear i.e. where the maximal profit point is.
From the manufacturers side, the situation is untenable too. If their profits are driven out of existence by price fixing from a huge buyer such as Wal-Mart, then they go out of business.
"So what?", you may say.
If they go out of business then all the people who worked for them are now on welfare. Not only is that a cost to you in the form of taxation but it is also a cost to your national economy as those people are no longer productive.
If this happens often enough you end up with an economy that is solely predicated on service industries rather than manufacturing. This means that you have a weaker economy, the wealth creating potential of which is very limited as a service industry job produces far fewer external ancilliary or supply chain jobs. I used to have a chart of this 'model' about twenty odd years ago and the difference is staggering

.
The long and the short of it is that if the consumer body does not work to prevent this then, in the end, everyone loses out. Even the shareholders of the corporate maw that created the problem in the first place lose out eventually, as if there's noone with any wealth to exploit then there's no profit.
Anyhow, if I go on much longer people will begin to fall asleep so I'll wrap up {"About time too, windbag!" shouts everyone :lol:}.