Cable Costs Relative to System


Since making a spread sheet with my audio system prices, I have been thinking(shocked) about my total investment in cables. My total system retails at $67,000 (Digital and analog front ends included). I purchased all of it here on Audiogon so my investment is about 50%. Of that I have about 10% invested in interconnects and cables and another 10% in Power Cables (Shunyata Hydra included). That's $13,000 worth of wire. I'm starting to question whether it might be more effective to put some of this budget into acitve components. It would take forever to listen to all possible combinations, but would like to hear others experiences with relatively high end systems and cable selection. It would seem to me that the point of diminishing returns would be reached sooner with cables than with speakers and amps. Do most of you follow the 10% "rule" for cabling? How do PCs fit into this rule? Are there any super bargain cables capable of keeping up with highly resolving electronics?
metaphysics
My current ratio is 32% ratio to retail price of all my cables in my main stereo system to 68% retail cost of my of my equipment. And the same ratios were for the actual costs. I found that interesting because my discount averaged to be 42% all equipment items. Even more strange is that I keep a VERY detailed Excel spreadsheet on all the money I spent, even upgrades sales gains and losses, for the past 10 years for all 3 of my stereo systems. LOL! ;-)
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I was just contemplating this very issue last night as I was fooling around in my audio room and it just struck me that my speaker cables, PAD Proteus Provectus, list for about what my Thiel CS6's do.

I bought both on a heavy discount but it seems insane, I love the sound so I just file it away as paradoxical.
@ pops, we know cables can make a difference, just depends on the cable and everything else in the system, To me the cables are the most profound part of a given system, I have used top cables on inferrior componets to result better than high cost componets many times over!, the cables are a componet!
No doubt Audiolab - as you very well know I am in that camp! LOL - it just seems strange...thats all! 350 lbs of speaker with wire, drivers, parts, furniture and then.....a wire. Some things you just can't understand like for instance.....how does the beam me up on Star Trek work? Or the phasers - I could use one of those - set to stun only of course...