Are interconnect cables worth $15,000?

No. Not in my universe.

I would say definitely, that is if you listen to music in a dust and noise free perfectly acoustic vacuum and only spin a record once before tossing it in the trash....and of course, you maybe run a hedge fund and just have lots of cash sitting around. I wouldnt recommend re-financing your house for them though.

only if you have Client #9 money

I had a great experience switching from my MIT-770 speaker cables ($3500) to MIT-850 triads ($9500). If you got the money go for it. I wish I could afford Tara Labs Omega series speaker cables, maybe someday.

A friend was demonstrating his new multi thousand buck cables to me recently ( i think they were nordost)I wasnt really paying much attention to the brand since I roll my own. His old cables were sitting nearby. When he left the room for awhile I switched the cables. He returned and we continued to listen for several hours. He never noticed and I never mentioned it. To this day he has never said anything about it. I cant wait to switch his new power cord out for the one from my old dell if I get the chance.