Freediver, I will politely disagree with your conclusion regarding the nature of components and benefit of cables. I have built many systems in the $2-5K range, and every one has been as sensitive to cable changes as the "big boy" rigs. No, you cannot expect precisely the same result as with better systems, but the cables do effect significantly - by that I mean easily heard and repeatable changes - even modest systems.
Two incidents to consider. The first system I tried to test cabling on was what would be a solid MidFi rig. It was nowhere in sight performance wise to what I can build now. My first cable test was some extremely thick cables purchased from a home improvement store, with such gauge that when I twisted all the individual conductors together I could barely fit them into the posts of the amp! Instantly I heard the difference between it and lamp cord, and I knew at that moment the wires are critical. That was a revelation which occurred on a system with compromised performance and with very average cable, but with large AWG.
My second "I don't believe it," moment occurred a few years ago when I had a boom box which took a C7 plug. I had just upgraded my power cord for Sonos to an aftermarket one, an Audioquest. I wondered if the difference in a power cord to a boom box could be heard. I knew enough not to discount the possibility altogether. Yup, it did make the boom box sound different, another evidence that cables matter no matter what the electronics. :)
