Power cord choice?

Hello,
My recommendation would be a Puritan PSM156 power conditioner. $2300 sound like a lot. If I had a $500 system today I would buy this power conditioner knowing what I know. It is that good. I would like to know which piece of equipment you are putting this one PC on. Also what are the models of the rest of your gear. I am a music audiophile but more importantly an equipment or gear audiophile. So I have heard the differences in several cables. If your system is not resolving enough you may not hear the difference or you need to correct the power from the wall first. Just add better ground rods (2) 8’ deep to your main breaker box will go really far. That panel and system is designed for your A/C, dryer, oven. Not your audio gear. Also, get you line going to your gear off your A/C phase or your refrigerator. It does make a difference. For what your asking out of the blue is a Nordost Blue Heaven. This is under $400. Even on my Denon surround receiver it took it to another level. If this is an amplifier go with Nordost Red Dawn and Blue Heaven on everything else. If you get a little more money in your budget go with Straightwire Black Thunder or even better Pro Thunder on the amp or preamp. Then Blue Heaven on the rest. On an amp you really need AWG of at least 14 AWG. Otherwise it’s like trying to run a marathon while breathing through a straw. If it’s an integrated go with the Black Thunder. If you have a CD player, DAC streamer that sounds a little too digital or a class D amp that is a little too dry go with the Puritan Classic plus. Really nice cable for $240 that really expands the decay. If you are in the Chicagoland area this store is a dealer:
https://holmaudio.com/
They let you try before you buy. I have several types of systems in my house so yes, I have tested all of this and I have a really good ear. I hope this helped. There are dealers all over the world for all of these products. 

I enjoyed @thyname ‘s post. I’ve thought for a while about how plumbing and electrical wiring are different. This explains why. Thank you!

WyWires is having a 10th anniversary sale. 40% off their platinum line.  $1000 power cord for $600 is in your price range.  I haven’t tried one before, just letting you know about the sale. 

Your amp and/or power conditioners are designed to take the raw power, filter it, clean it, do all the other magic and then send the signal to your speakers.

Ok, firstly amplification has no “magic”. IOW, Gandalf plays no role here.
A power supply job is to rectify a 50-60Hz AC supply, rectify it and remove all ripple (read AC) from the DC output. 

An AC signal is not raw, nor is a DC signal cooked; Gordon Ramsey doesn’t play into amplification. Less noise on the AC source will ALWAYS result in less noise on the DC output from the power supply. ALWAYS and every time without exception.

The amplifier stage then receives the DC supply and makes a copy of the input signal using the DC supply, which end up going down the speaker cables. If the DC supply coming from the power supply is not perfectly ripple free, your sound is compromised.

How do we believe a 3 foot piece of cable, from the wall socket to the amp is going to change the sound coming out of the speakers?

Because the “3 foot” cable acts as a filter and reduces noise from the AC before it enters the the amplifier’s power supply. The cleaner the AC that enters the power supply, the cleaner the DC will be that it produces. The cleaner the DC, the better the sound.

The idea that a power cable won’t help, is pure ignorance. If you obtain understanding of how amplifiers work, it will become very clear why cables improve sound.

turnbowm

If a power conditioner has a negative effect on sound. then it’s not a GOOD one.

I think the real world is not so simple, even if your claim is made in ALLCAPS. For example, a system’s sound can be influenced by the exact location of the power conditioner relative to the other components, and it’s also possible that removing distortion may be heard as a loss of detail, even if the the signal is actually more accurate. Describing a sound as a "negative effect" is really subjective.

An example would be a series-mode surge suppression/conditioner that doesn’t use Power Factor (energy reserve) technology. The result would be reduced dynamics and bass impact due to dynamic current-starving of a power amp.

That’s nonsense.

For one thing, in residential environments, electric utilities are very good at keeping PF very close to 1, which is the ideal. (You can easily measure this for yourself to confirm.) Even if the PF is slightly negative, you’re still likely to be able to pull 20A from a 20A line. PF is much more likely to be a problem in commercial areas where you have motors with inductive loads.

Far more likely to be a power issue in residential environments is not PF, but the utility’s ability to deliver current on demand. For example, while you may have a 200A panel at your electric service entrance, that’s no assurance at all that the utility can actually deliver 200A to you. A prime benefit of power conditioners with energy reserves is ensuring power on demand; PF is only part of it.