Not all ethernet cables are unshielded. Shielded twisted pair (STP) does exist as a cable standard, but is rarely used in modern networks.

But I do agree completely that this is a scam pure and simple. With a cat-5, cat-5e or cat-6 cable the cable either meets spec or it doesn't. There is no practical difference between a $5, $10, $100 or $500 cat-6 cable of the same length.

The only difference that really affects price is whether the cable is plenum rated or not. And looking at the denon cable, it isn't even plenum rated, so for all those who want to wire up their house by running cable in wall, it's absolutely useless.

It's pretty much the same story for any of the digital cable standards. One cable that meets spec is just as good as any other cable that meets spec regardless of build quality and price.

A digital cable that performs better than the standard spec for which it is used is a waste of money since the extra bandwidth will never be used.