Expensive cords would not be of benefit to me. I use just ONE outlet for all my systems, to minimize ground loops and such.
My total system wattage is about 1200 watts.
First thing into the outlet is a Brickwall Surge Suppressor.
Then plugged into that is a 2400w LC2400 Tripplite Power Conditioner/Regulator. Then audio and video are split up with a large surge suppressor, and the audio is fed with a 10' heavy duty extention, to two surge suppressor strips.
So a 3-5' expensive cord makes no sense in my system.
What I should do is get a heavier extention for that 10' length.
But I assume most of my units have good power supplies, so I am not too worried about that stuff.
Of course you could put your power amp directly into a wall outlet with an expensive cord. YOur choice. But when a surge or brownout zaps your amp, you had better hope the technician replaces your expensive parts with equivenlent quality parts. Chances are, your blown out $5 capacitor will get a fifty cent replacement, and the sound degradation will be more than the improvement of the expensive power cord.