As usual Rick, you have put your finger on why this lunatic is dangerous.
The problem we are having is that as G.K. Chesterton said you can't argue with a lunatic, or you are inclined to get the worst of it.
The fact is that auditioning those cables is a crude experiment. To perform any experiment you have to have a plausible hypothesis as to why the experiment is worth doing. There is no plausible explanation as to why a power cord could make a difference to the sound you hear.
So, before doing the experiment you have to have a theory of possible improvement based on the known properties of conductors and electron transfer. None of these are offered. Looking for an effect without a reasonable hypothesis is the very definition of magic, exactly like witchdoctor would.
Now that $16,000 power cord would buy a really nice set of speakers, that would make an improvement, and support a valid manufacturer and vendor, and not magicians.
The other issue, is that I bet when we have a post about a ground loop, by far the commonest powering question asked here, this witchdoctor will advise an expensive cable. No matter how much the cable cost it will NOT solve a ground loop.
I would bet big money this witchdoctor does not know the first thing about a ground loop, and could not help a poster solve the problem.
It is easy to laugh at this kind of nonsense, but it has a serious side and is a scam that cynically deprives people of their hard earned money to a con artist with no benefit whatever accruing to the customer.
It is some time since we have had such a brazen con artist on these forums, and it is now past time for a mod to use his ban button.