The rich person buys quality furniture that lasts a lifetime and holds its value (if not in fact, appreciating in value). The poor person rents-to-own crappy furniture that doesn't outlast the payments. The rich person buys a car and gets the best possible price - as well as the best financing terms - as he has more sophistication and an 800 credit score. The poor person pays through the nose, often paying more than the rich person, for less car - and paying more in interest than the purchase price.
Again, if you are smart and think about these things, you can come out ahead. And the common denominator for both the poor consumer and the rich consumer is status. If you have a high income, you can go and blow every last penny on consumer goods, chasing status, and wonder where all the money went. Or, you can live below your means and accumulate wealth. This does mean having people laugh at you for driving a cheap car, instead of an expensive one. But people like that are shallow anyway, so why bother dealing with them.
Similarly, for the person with a lower income, if you can eschew status-seeking, you can avoid a lot of really rotten shitty deals that take what little money you have and squander it. Renting to own furniture may sound like fun, but it doubles or triples the cost of the furniture. Similarly, if you are living in a $25,000 trailer home, maybe you should think carefully before you buy a $50,000 pickup truck. Both are depreciating assets, of course.
And sadly, the rich person is more likely (but not always!) to figure this out, as they have more education and are (supposedly) more sophisticated. In recent years, however, it seems the "shrinking middle class" is getting dumber and dumber (and hence the shrinking) and chasing after status. Ordinary people are getting that wild-eyed look in their eyes and saying things like, "leasing a new BMW makes sense! I get more car for my money!" - and then they blame Obama or the GOP when "someone takes my money away!"
I have found, over the years, that some of the cheapest products I have bought are the most satisfying, mostly because their being cheap means that they seem like such a better bargain, as time goes on. Even if the car doesn't have a three-pointed star on the hood, or some fancy feature you'd never use anyway, you find comfort in the fact you spent hardly anything at all on it, and moreover, you worry less about it getting damaged, stolen, or breaking down.
The poor will continue to make poor choices, I'm afraid. There isn't much you can do to educate Mr. & Mrs. Redneck about that. The middle class, however, who went to college - what's their excuse? You can work this marginal pricing thing to your advantage, and end up with money left over which is how one accumulates wealth in the first place.
Live below your income. It's that simple.