Well, why is a Ferrari car more expensive than a Skoda, or why do diamonds cost more than glass? 
One is not comparing like with like.  Apart from the superior quality cable and plugs, the brain of the 
system is a filter unit par excellence. It seem strange that some people are willing to spend huge sums
of money on their hi-fi system and speaker cables yet negate this by using poor quality, inferior 
power line/distribution sockets. A system is only as good as its weakest link!!