Are upgraded power cables really worth the money?


My system consists of musical fidelity a5 integraded and cd player, b&w 703 and a rel 305 sub. I'm Im using purist audio musaeus interconects and speaker cables. I understand and can certainly see how these cables have helped my system, but am a bit aprehensive about investing in upgraded mains cables. Do they really make much difference? With the system I have what would be the right amount to spend on them. Any suggestions?
zeekzaak
Previously, I had no opinion on the matter because I had not tried quality commercial aftermarket cords in my system.

Just got some Black Sand Siver Ref MkV w/ upgraded Oyaide plugs.

These cords made an easily noticable improvement in the sound, esp. the bass which is much deeper and tighter.

I can't beleive that someone couldn't, with the right but still simple test equipment, measure this effect and put this whole thing to rest, the change seemed so significant.

Only you can decide if it's woth the $$.
Should have added - One cord for a VAC PA100/100 amp and one for VAC Standard LE MKII pre. In comparison to Volex 14 ga that I had put upgraded ends on.
Here's a question from a skeptic on the issue of power cords. Given that your house is wired with standard residential wiring (extremely inexpensive stuff), and that that wiring comes at the very end of a line running from a power station located miles away, how is it that 3 feet of expensive power cord is supposed to offer some kind of upgrade? And if it did upgrade things, why wouldn't it make more sense to build a power cord that was, say, 2 feet 11 inches of house wiring, and 1 inch of super-expensive power cord?
That is a very old question which has been answered many many times. Do some research.
"That is a very old question which has been answered many many times. Do some research."

I took your advice, or perhaps I should say, followed your order, and discovered two things. 1)No blind test has ever shown that anyone has ever been able to distinguish a $10 power cord from an $800 power cord. 2) Wolff Auduio sells $800 power cords.