At a certain price point you account for the quality of the materials and assembly of most cables. This then becomes a world of differences not improvements. Millercarbon actually does make a good point-- you have to take the time to learn how to listen, and I would add one thing to that-- don't waste your time making snap judgements. Sometimes hearing differences also includes trading one perception (mental focusing) for another.
This is why if I make a system change (I like to think I'm making an upgrade) I try hard to set my snap (or blink) judgements aside and just live with the change for a while, listen to a lot of different music, and slowly come around to my opinion as to whether or not I believe, from a lot of listening, that it is indeed better -- better for me.
Again, Millercarbon's comment on replacing his speakers with a much less expensive set that, to his ears, sounds better-- then it is better. There's no arguing the absolute truth of a proposition like this because we're all different and we all hear differently.
I'm not saying that junk will sound as good as something decent or better, just that at a certain point it's a matter of taste-- and that taste is ultimately a personal thing that cannot be objectified.
Every system, every room, and every person is different. Especially when listening over time, everyone will respond differently to the same stimulus based upon the biggest variable of all-- you. Never fall into the trap that more money equals better sound and therefore more enjoyment, it just ain't so-- no matter what that salesman or that review or that advertisement says. Learn to relax and to just listen to the music and not the gear-- you'll find your truth in time.