I do not see any need to pay esoteric prices for a cable either. The cable and the interconnects do however need to be up to the job. And yes, arguably there can be a predictable and measurable difference. I personally dont see the harm in adjusting my treble a few tenths of a dB. After all, what do you think happens at the recording studio?
Beyond that, cables can be measured quite effectively with the right equipment. Here is a link I have posted a few times showing how much change in inductance you can get with two 36" test leads.
http://www.woofertester.com/measurecable.htm
If anyone is going to the CES, Smith & Larson Audio will be showing off the Woofer Tester 2, Woofer Tester Pro and Speaker Tester at our booth, #404 in the High Performance Audio Venue at the Venetian convention center. This demo is pretty easy to show. We will have other stuff there as well.
Best regards,
Keith Larson (WT-Pro)
Smith & Larson Audio