I did sound reinforcement for just shy of a year and a half. I worked with a team of 4 or so and our supervisor who was a big tech head on the side of SR, electrical theory and all the science behind it that I didn't fully understand. For analog signals the cables make a difference only so far as the electrical resistance of the wires themselves. Some run quad wires to cancel out interference and noise that gets through the shielding, but mostly the only differences are going to be:
Signal carrying metal material
sheilding method
connecting points (quality of soldering, etc)
external material (not important for signal, but for longevity of cable)
$1000 cables are a farce. They're making $990 profit. I've built cables myself, soldered the connection points, had to open up cables with shorts and foud how poorly they were put together. No fault of the wire itself, just the person attaching the end plug onto it.
I had to strip the old bad-quality connectors off a few perfectly fine cables and added on better ones with fresh connections because I'd do it better than whoever made them in the first place.
So yes, the quality of a cable can vary, but not THAT much. Not $1000 worth. Also, the quality of a digital cable is totally different, as well. Different electircal requirements.