Crwilson, hmm, you are right, you can find bad quality at any price point.
Aside from construction, when I say quality I am talking primarily about the fabric. Better fabrics are going to cost more. I would not include knitwear because knitwear at any price point is, well, knitwear. It all eventually pills and fades or stretches out etc. That is the nature of the material.
I think it's easier to compare quality if you compare suiting from store to store. F21 suiting is going to be of lower quality than H&M. H&M will be lower quality than Express. Express will be lower quality than Ann Taylor. Ann Taylor and BR will be about par, but BR Monogram quality will be higher. Jcrew - I can't speak of but I've heard their suiting quality is very good.
Now go into the higher end labels like Theory, Vince, Nanette Lapore, DVF, Calvin Klein and on up.... and compare the quality of the suiting material. Hugo Boss was the brand of sheath dress I tried on. It was a $700-800 dress. You could feel the difference - the extra $ were all about the fabric.
There's also a big difference between a white shirt from BR/AT and from, say, Ann Fontaine. You can feel the difference when you touch the fabrics. You pay a premium for AF shirts not just because of the meticulous detailing, but because the material is simply luxurious. (With that said, I did recently buy a white sleeveless AT blouse that does feel luxurious! When I find something like that among the racks, I rejoice!)
I think I notice these differences for two reasons. One, my mother is a seamstress so I grew up around fabric stores. Two, my dad was an executive and had a closet full of expensive suits. (He also shined his shoes every single day, which made me grow up to appreciate nicely cared for shoes).
But, in my dream world, where I am reincarnated with San's gorgeous tall figure, I would not necessarily ONLY buy higher-end stuff. The cheaper stuff is loads of fun and a closet would be boring without it. But I would buy the best quality I could afford and find for basics like suit jackets, white shirts, pencil skirts, dress slacks, sheaths. The wardrobe workhorses. Make sense?