Power Cables diminishing returns

I'm thinking of upgrading my PCs, but am wondering what the sweat spot is as far as price. The price point after which, you see diminishing returns. for example a $1000 is certainly not twice as good as a $500 cable.
I highly doubt if any big corp doesn't see LOTS of taxpayer cash. if only through the 8000 plus tax dodges their lobby lads have provided them.
Big Pharma got hundreds of billions when their lobby got Medicare D, aka Pharma Profits Act, passed with the no negotiating proviso.
VA pays 1/3 of what Medicare pays, big Pharma wasn't going to allow that to happen again.
"08-12-13: Drummermitchell
Perhaps every 250.00+ pc cable,interconnect,SC ect should come with it's own recorder so we can hear the huge difference,recording doesn't lie.
Not one cable manufacturer has a before and after recording(do they)of the effect their cable makes on the sound.
Perhaps a Zoom H-2 handheld digital recorder will let us hear what's really going on."

Maybe. But why record it if you can listen to it for real? The only upside I can think of to recording your stereo is that the absolute sound becomes your stereo system. Never thought I'd make that statement.
Maybe with a blindfold on you can't tell whether you are riding down the road in a Ferrari or a Toyota? That doesn't mean the guy who bought the Ferrari was wrong or stupid.
Wildoats, you will also have to block my ears, so they won't hear Ferrari:-). That also doesn't mean that guy who bought Ferrari was smart or one who bought Toyota was stupid. In most of the cases, trust me, it's vice versa.
Put a bi directional ac noise blocking cord on your digital.
Put the best ac filtering cord you can afford on your pre.
Make your own 10 gauge cord from materials at home depot for your amp. They will give your easy instructions, might even help you with it on a quiet day. There's isolation for your digital, conditioning for the precious small signals in pre and fast current for the aamp. Good start. Used cords are great value.