Cat6 solid core can do this for 1Gbps (~1GHz), this makes me wonder about skin effect for audio cables.

Cat6 can do 10Gbps but it may not go as far in distance as Cat7.

Cat 7...man.
First: "Category 7 is not recognized by the TIA/EIA."
https://en.wikipedia.org/wiki/ISO/IEC_11801#CAT7

Second: those Newegg cables might not pass Cat 5e. If you're buying it from a consumer market retailer than I would genuinely doubt it's anywhere near Cat 7.
https://www.bluejeanscable.com/articles/is-your-cat6-a-dog.htm

Wether is recognized by TIA/EIA or not, I know most Cat7 can do 10Gbps. At least the Belden samples we got quite a few years ago did while I was at another company. I worked on the 10GBase-T PHY. In fact, Cat 5e can also do 10Gbps... up to 50 meters. Though I think I got that to work quite a few meters further than that.

That sample cable is like 10ft. 10ft of Cat 5e w/o any patch panels to worry about should do 10Gbps in its sleep. $5 of overkill right there.

(EDIT: Shut! Should have said meters - we use to have an inside joke "100 meters, 100%", so 10ft is like peanuts.)

(EDIT2: Note 10GBase-T transceivers use quite a bit of adaptive equalization not just for cable but to counter all kinds of echo which your average good-looking ill-functioning mega-buck "shine it must, work it might" audio interface may not have. But the capacity is definitively there.)

http://arstechnica.com/gadgets/2015/07/gallery-we-tear-apart-a-340-audiophile-ethernet-cable-and-look-inside/

Silver coated ethernet cables indeed.

Interesting indeed! I wonder what are the time and voltage resolution settings in that scope?

K, anything Cardas does needs to be repeated under controlled conditions. Sorry if I don't trust someone who claims to have invented neodymium for use in his 'earspeakers'.

I'd say this is probably because of that steel table plate. Who has floor made of this?

non twisted pair
and exposed barrel touching said metal table
etc