Absolute snake oil. There is nothing in this world short of making it out of platinum that could possibly justify an IEC cable costing $1500 or more. Or any cable, for that matter. If you have money to throw away on such things, hats off to you. As long as you're happy.
Personally, I'd rather apply that money to the acoustics in my listening room (one of the most overlooked, but 'hearable' tweaks you will ever apply), or more media.
The notion that you can 'hear' an AC cable flys in the face of common sense. There have been too many failed 'blind' tests, convincing test data (please don't tell me your hearing is more acute than electronic test equipment!) and not to mention the laws of physics . Those reasons alone should be enough to explain away any desire to purchase this stuff. Couple that with the complete lack of eveidence supplied by the manufacturers (if they actually DO manufacture their own cable. Most DO NOT!) to back up their claims and there you have a good old fashined bottle of Doctor Bob's cure-all tonic!
Ok guys, go ahead and shoot me ;) Just expressing my opinion (which is based upon my education, background and some reasonable research into the subject, not on rituals involving chicken blood or anything like that.)