How can power cords make a difference?

OK, my first post here so be gentle ;)

Pardon my ignorance. I may have missed the answer but 'logic' dictates that super esoteric (read VERY expensive) power cables would not make a difference for one (IMHO) simple reason:

Indeed I could see how ensuring the mechanical contact (on either end) is as good as possible but otherwise what difference would the last 5-6 feet of '6 ga multi-stranded platinum alloy, laser end cut terminated in pure 24ct gold' power cables make when the previous power feed (up to the aforementioned 'super' cable) is nothing more than run of the mill 3 strand bulk romex?

You hit the nail on the head redkiwi (re: my assumption that the only purpose of a power cord is to transfer volts and current from the wall to the component). I certainly don't mean to appear snide whatsoever, but what other purpose does a power cord serve?

Thus my unsophisticated observation that beyond gauge and mechanical connection, everything else might be, umm... great marketing?

Beyond that, I could definately see how noise shielding might be beneficial even tho, as others apparently have before me, my own 'logic' surmises the components power supply should rectify (no pun intended) any potential problems in this area. And I would think certainly so if the component is considered high end, audiophile quality.

Unfortunately it's a moot point for me. At 53 yoa I doubt my poor ol ears could discern what would have to be very subtle differences in sound quality. I just wanted to better understand how/why someone would pay up to $2K for a power cable.

In any case, whether real or perceived, I envy you and others that CAN hear a difference in reproduced music simply by changing a power cord.

Just so everyone knows where I'm coming from, I'm not of the opinion that stock power cords are in every case 'totally sufficient' and a system cannot benefit from a better quality cable, e.g. I can certainly wholeheartedly agree that anything that might lower resistance, improve mechanical connection & reduce potential interference, etc. beyond what the current cable provides (no pun intended) is a good thing.

Rather, I'm just thinking there has to be a point of diminishing returns... that once you reach a certain minimum/maximum level of achieving the above any further effort is simply beating a dead horse. That is, in all seriousness can a $1500-2000 (retail) power cable provide that much improvement over a $500 (retail) one to warrant the difference in cost?

Of course my simplistic view doesn't take into account the 'psychology' inherent in audiophiles that creates the ever present quest to achieve totally perfect sound reproduction . And I thus suppose the point at which an audiophile begins to 'beat a dead horse' is, bottom line, only dictated by his/her budget. My hats off to those that can pursue this 'ultimate goal' with a system budget that (in more than a few cases) exceeds the cost of my house ;)

I know this is the wrong forum for this (not sure which one I should present this in anyway) but it seems there are a lot of extremely knowledgable people in this forum and since I sorta have your attention here goes:

I'm placing myself before you on how/where to proceed in improving my modest audio/HT system. It is as follows:

Sony 36" TV (no component vid, just S-video)
Harman Kardon AV500 (70w X 5 channels)
Sony DVP-S3000 DVD
Denon DCD-2000 CD (RCA's to HK)
Carver M400t
JBL L100's (for left/right)
JBL TLX-Center2 (center)
3 way in-wall JBL's (for surround)
Dahlquist 12" sub (150 RMS, 400w peak)

The HK L/R preout drives the Carver M400t while the HK's own internal amp directly drives the centers/rears (of course the HK's sub out goes to the active sub). My 'theory' is if I use a seperate 'L/R' power amp I reach an acceptable compromise between my (2 chan) music and (5.1 chan) HT needs. Sound levels are balanced to within 1 Db using sound level meter.

All interconnects are optical or S-video where possible. Pre-amp to power amp interconnect is heavy Monster cable (RCA's). Sub out to sub is heavy monster cable (RCA's). Speaker interconnects are 14 ga stranded monster (tinned wire ends). Power cables are 'stock' ;)

All components (except Carver) sit in a rigid 'entertainment center' constructed from 'formica like' covered 1" MDF. Shelves are same but 5/8" (and themselves sit on small adjustable 'pegs'). No isolation/damping pads used. Carver sits on (non pile carpted) floor. JBL's sit on oak topped steel legged tables to raise them to ear level. They are spaced (approx) 8' apart and L/R & center is within 2" of 10 feet from the 'sweet spot' listening position. Rears are (in-wall) approx 11' behind and 6 1/2 ' from the floor.

I believe my next 'big' investment (everything is relative ;) is to fully re-cone my L-100's ($600). While they're sounding good and otherwise in good shape, just the fact they are 20 years old leads me to think it's getting about time. I just love they way these speakers sound which prevents me from thinking of replacing them entirely. I just don't think I could obtain better range/imaging speakers for a similar cost. Thoughts?.

One of my current dilemmas is while the rears seem fine, the (newer) JBL center speaker (while sounding fine on it's own) doesn't match the umm.. rich 'tonality' of the L-100's. Not sure how to resolve this (short of just trying out speaker after speaker).

Another quandry I face is my 14x20 'media/living' room (in a small condo) is rather bright. At louder volumes (-5 to 0 Db) I'm getting all sorts of reflections and often higher freqs seems to 'resonate' at times (resulting in my suddenly paying more attention to the 'defect' than the music/movie). At least I think it's the room that is causing this since lower volumes (-5 to -15 Db) doesn't seem to produce the 'resonance'.

So, anyone have any suggestions how I might 'evolve' from this point? How I might improve this system and/or sound (considering I'm on a pretty tight budget)?

Any advice/suggestions will be VERY much appreciated.