As Danny pointed out in the video that bolong provided a link to and most didn't bother to watch, it's not costly in the least. He made his with some Tinker Toys his kids had. Two other friends who thought him crazy bought some after he demonstrated it to them. He said it took all of 5-10 seconds for them to hear the difference and they were on their cell phones ordering Tinker Toys from Amazon.
He also points out that not every cable is going to benefit from it and not every system is resolving enough to appreciate the differences. Why is everyone getting so emotional about something so inconsequential and instead, creating false narratives as if there's only costly and ineffective ways to doing it?
All the best,
Nonoise