In my own experiences, I find that higher price = higher quality.
But, a person has to know what's worth spending money on, and what should be skimped.
I have a couple of plain tees from Target, and I find they don't fit me as nicely as something from a name brand might. But, I bought these tees specifically to wear at home, and I wear them all the time. The material is much thicker than the plain tees that we see in higher-end stores (even at mid-priced ones like Aritzia), but.....they're frumpy and pretty ugly, to be honest. They're more durable, but their aesthetic appeal make them confined to days when I'm at home or days when I'm sick.
That being said, if I'm looking for a nicer, trendy sweater made out of some good material that will last a considerable amount of time...I'm forking over the extra money.
In terms of good quality jeans? TRs and Paiges. I had no idea what quality jeans were until I put these on. Unfortunately, TRs make me look disproportionately large below the waist.
I'm one of the lucky ones; I have yet had any of my R&Rs rip on me. Despite the mediocre quality, they're actually one of the brands that I find look soo good on people.