As a rule, fashion doesn't matter at all. I dress alright and probably spend way too freaking much on clothes. My main targets are reliability, sensibility, precision, and aesthetics (to me, at least). This means a lot of solid colors, some simple patterns, and stuff that is really durable and/or precise.
I wear Doc Martens because the old Made in England ones lasted a really long time and were exceptionally comfortable, which meant they compared favorably to cheaper shoes. The style didn't matter to me. The new Chinese ones suck (and feel crappy), so I'm planning to get some Solovair shoes next time (those are actually made in England and produced by one of the same companies that made the old Doc Martens). Basically, I like stuff I can depend on. Quality clothing from certain name/designer brands (not their outlet center stuff) seems to last distinctly longer than cheap clothing. Then again, the same is true of most US-made clothing.
I bought some cheaper stuff recently because that's where mom wanted to go, and it really shows in the rate of wear. I've lost three shirts in less than a year to wear due to their lower quality, while I have a long-sleeve Polo shirt that I wore in my regular rotation (once a week) for 6 years and it shows only minor wear. Loss of buttons on the pockets of cheaper pants is an ongoing problem, too...
On Saturday I realized that on an average day I'm wearing/carrying ~1.4k worth of stuff between my cell phone, ipod, sunglasses, clothes, shoes, knife, belt, etc. The majority of that is in my cell phone, sunglasses, and ipod (1k worth of it), followed by concentrations in my shoes, knife, and belt, while actual clothing only accounts for about 120-150 of the total most days. Winter outfitting adds about 500-600 to that. My laptop bag adds about 3k when I'm carrying it, down from 6k 5 years ago.
When I went for a walk down to the border on Saturday, and standing where I was on the north side (which is almost entirely devoid of life) with the masses of people on the south side looking through the fence at me, the disparity is amazing. I mean, I was wearing and carrying probably 3-5 years worth of income for some of the people on the other side of that fence... It doesn't surprise me at all that that they will brave dangerous crossings and work for next-to-nothing in the US.