I'm the same way. I just use cheap high quality junk for my speakers and can't hear a difference. I believed the same for headphones until I got into recabling my headphones. The bad news is that every brand of wire sounded different to me?! Some headphones benefit more from recables than others. You know how when you buy a cheap DVD/VHS player they throw in a 20 cent RCA cable? I kind of think of stock headphone cables being just like this. As cheap as possible, but not always. I mean it's always super thin. Like how could that NOT hurt sound quality?
Biggest difference I've heard was when I recabled my HD-598 to Mogami.
I also was dumb enough to recable my KSC75 with silver. No, I don't suggest it!
I wish all wire sounded the same. It'd make my life a whole lot easier. Why can't they just all sound equally good? I'm still not convinced any cable could be worth $80+ for 6 feet. Maybe someday when I get rich. I don't feel like paying a 300% markup on pre-built cables. Mogami is good enough for me. Now with interconnect cables it's nearly impossible to tell the difference at least with my ears.