Sounds like hogwash to me. Snake oil salesmen of old have mostly been reincarnated as audio salesmen. For some folks though, half of their enjoyment comes from bragging about how much they have spent/(wasted?) on audio equipment. I try to ignore folks like these because I hear them talk about "Skin effect" or the sound that you get from a certain speaker wire, not referring to its gauge. Well, I used to maintain a 2MW UHF CH61 so we had hollow center conductors in our transmission lines because of skin effect. I just don't want to hear that mentioned at baseband audio though. Then there were all of those high end amps with the super specs for big $$$. They just sounded like garbage unless they had a few hours to warm up. The worst part is when they are owned by the folks who blast them because their ears are probably shot above 12kHz.

I think they should save their money and spend it on something practical like a Cessna Mustang, or a ride on a Virgin Airlines spaceship.

Just make sure he picks up his $30,000 / roll cable instead of expecting you to buy it for the job. And remember to charge him extra for the installation because you have to sprinkle it with half an ounce of pixie dust per foot for it to be effective.
Joe