Which of these power cords ?

Chinook91 you are absolutely correct in your skepticism.  The typical in house wiring, in the US, is a 15 amp circuit with 14 gauge wire and could easily run 50 feet or more.  This terminates at a circuit box and a breaker on one end and an outlet at the other end.  All of this will have much more impedance, discontinuities, etc, than the last few feet of cable.  If it is worth spending thousands of dollars for the last 3 to 6 feet, then it must make sense to spend $100K or more for the wiring from the power company connection to the outlets these cables are plugging into.  This is just a really good way for cable companies to make a ton of money from people that don't understand physics.

That said, the placebo effect is proven to be real, so I'm sure people that spend $5K on a PC can hear the difference.

On the contrary, the power cord is the first 3 to 6 feet outside of the component that alters the performance.

In my system Power Chord swapping is easy to hear the differences...the same power cord on my DAC can sound vastly different on my preamplifier and again on my amplifier. I enjoy trying new power cords and have collected a lot of them. The Black Sand Audio is a great sounding cord on all my equipment and at a fair price...I purchased mine used in good condition. 

 I have an audio only subpanel with 8 dedicated circuits of 20 amps each per outlet in the listening room isolated from the lighting and HVAC servicing the room which goes to another subpanel.  The audio power outlets have Synergistic Research Blue duplexes.  The wiring is 10 gauge.  I built the room for listening purposes only.  The 42,000 LPs/78s/CDs are housed in an adjacent storage room and record storage Tuffshed.

I have the DH Labs Red Wave power cable on my amp. It's the biggest single improvement I've ever experienced, I was amazed.