AC Power cords, which components 1st...?


I've been lying in the background with regard to upgrading power cords and I'm now thinking that I might give it a try. I fully subscribe to the laws of diminishing returns with the exponential (if not worse) price curves of these products. Therefore, I'd be looking in the $50 - $250 dollar price range. I don't need long cables (3 - 4 ft should work) and that may help the price point. Pre-owned is fine with me as well.
Given that, which components first? power amps, pre-amp, source...? and, any thought on power cord given my predisposition?
Aloia power amps, Casanova pre/pro. Capitole MKII (soon, I hope).
Thanks
rap
Thanks all...a lot to consider.
When my dedicated 20 amp lines were installed several years ago I installed standard "hospital grade" outlets. That was before this new buzz/hype with regard to the audio grade outlets. Anyone know what the composition is in the hospital outlets?
I have several audio grade outlets but have not a/b compared them (too much hassle). And I don't really put a lot of stock in them but it's such an inexpensive upgrade it doesn't hurt to have them.

What I have discovered though, is that most any cheap or expensive 20 amp outlet will grasp a plug much tighter than a cheap 15 amp outlet.

-IMO
My system is not a big investment ca. 8M though a good ammount of time has been dedicated to feed it the best in cost /performance in mind and set up and tweaks have really improved the quality of the sound coming out of it.
As part of this process have dedicated lines and also I have changed PC in my source, preamp amp and the results have helped quite a bit. I´m very satisfied with the where the performance of the system has climbed to.
"The old saying about "garbage in ... garbage out" is certainly true in audio as well. If you send a dirty signal to the amp, you will just amplify the dirty signal. So, at least start with the CD player, and then work towards the end of the chain."

This doesn't isn't really clear, as there is no difference if my pre-amp adds 1% distortion or my power amp adds 1% distortion. The source of this folklore is of course the tt manufacturer Linn to help them seel higher priced turntables. When a mechanical device is the source it needs much more attention to setup and quality to retrieve the information available. Today any cd player will retrieve all the info available on disk with minor differences between them. So this isn't the reason to choose where to put a power cord.

steve