why do people feel the need to buy expensive cable


I have tried expensive cables and one's moderately priced. I would say there were some differences but I can't actually say the expensive cables were better. IMHO I believe a lot of people buy expensive cables because they don't actual trust their ears and are afraid of making a mistake. They figure the expensive cables are better for the fact they cost more. If you have a difference of opinion or share the same thoughts, I would like to hear about it.
taters
"Sounds real scientific."

Way more scientific than Joe Schmoe switching from $200 RCA connects to $1000 connects and reporting that the improvement was "awesome and unbelievable" and "the bottom end clarity was breathtakingly better."
I see cables priced well beyond what I've paid for my system. As a guy that has jammed cigarette butts into my ears due to lack of earplugs running a 120lb jackhammer I can honestly say, I'll never hear the difference. 
Quality cables are a must if you want to get the best out of your system. I've known people who upgraded their speakers or other components before upgrading the cabling in their system. At the very least, get cables that can make your system perform and you don't have to go broke. Belden 8402  mic cable is a good place to start cheap. Kimber also has inexpensive cables that are solid. High end systems need cables that will bring out the most, that's the only reason to spend big bucks on cables.