...people either have no experience with trying cables...
Probably true.
...have cheap equipment...
So it requires hi-end gear to notice a difference? Then cable choice is irrelevant for people without Eggleston Works and Halcro in their system.
Furthermore, if it requires ultrahigh quality gear to notice a difference, can it really be that big of a difference? I mean, if a a set of Revel F12's have too much "grain" to make the difference in cables detectable, is it really going to be a "night and day difference" with a pair of Ultima Salon2's?
...poor set-up and position...
If a cable can make a "marked change in sound", the setup must be
very poor.
If the room has bad acoustics, choice of cable is the least of that persons audio problems.
...or an ear that cant detect changes...
Than those who cannot hear the difference will be happy to be saving the money.
...or some hybrid of some or all of these problems...
And I would
not want to watch a movie at those peoples houses.
...or simply follow a opinion of somebody who is skeptical...
Unfortunately often true; people should prove things to themselves.
but the simple truth is that many cables do make a marked change in sound.
Of course they can, but a good cable shouldn't. And aside form high inductance, or capacitance, how does a cable make a vast improvement in sound quality?
Think about it, by what electrical process would a pair of Nordost sound better than a pair of AQ's? If we excuse perceptual bias for a moment and assume there is a great sonic difference, there is only one possible reasons for it; one cable is producing much higher distortion than the other. But the question then is; what kind of distortion could a length of copper introduce that would have an effect on sound stage (which is mostly dependent on the room, by the way)? Or on detail? High enough inductance will attenuate high frequencies, but what would a cable need to do to altar the waveform to make music more "beautifully listenable"?
But to answer your question, AudioQuest interconnects on my stereo, and generic and Monster in my home theater. A grand total of ~$175 for all speaker wire and interconnects.