almostthere,

since that's the case, then why is everybody saying that getting that 1kW PSU will give a large sum of electricity bill?     

Nowadays wee see that the current hardware uses more power each day. Those times where a 300W PSU should be more then enough is long gone.

It seems that the hardware manufacturer especially the video card/GPU and some CPU maker also doesnt care enough on the power consumption as long as it can deliver super high performance with their card. Rarely we seen an advertisment that says "New 9900GTX super fast performance with only 50W power consumption!" since the consumer itself doesnt bother much about the energy they waste. And they could care less since the power consumption is still considered small compare to Air Conditioner and Refrigerator.

But when is this more power more performance theory will go on? Do we really need a video card that eat 500W of power? Maybe in future some Computer organization should draw a line on the maximum power consumption on several parts of the computer like the FIA did with Formula One Engine, example maximum power usage of graphic card is 100W per card. And with that, GPU manufacturer will mostly competing on making a high performance card and yet low power consumption that will surely benefit our eco system.

Therefor this will surely benefit us consumer interms of electricity bills and dont have to buy new PSU unit when new graphic card is launched as well as saving those furry lil animals from extinction.