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
It's a process. I think you have to be patient. I also think you are the judge of what your system needs.  Find something that's good.  Find a match and live with it.  I think those who have more income are able to try the higher priced stuff.  I'm glad that I have been able to own some of the high fidelity products as well as listen to Rick's system.  I also listened to the late Dave baskin's system. Both systems were uber expensive but they sounded great.  However they were polar opposites and sounded nothing alike.  We have to appreciate the music and what your system does and enjoy it all.  Not obsess over it.  

I get quite dramatic differences in sound reproduction with different companies and price points. I have come to believe that Power Cables are as important as anything, even on kit you might not expect to respond. I was frankly astonished at the effect of a Lessloss Origonal cable on the Power Supply of my TW Accustic Raven one turntable, having expected little or no difference.

 What brands and price points, well I am afraid that depends on your system and ears and it really comes down to "suck it and see". A big plus here is the second hand market, I never by new if possible. Used cable cable is usually at a good discount and the origonal owner has kindly burnt it in for you, plus performance should be 100%, unless the cable has been seriously abused.

 Currently, I have found that Lessloss, Sablon audio, Silnote and Wywires , give pretty good performance for their cost. No coincidence I think, that they all small companies relying on shows and word of mouth, not hefty marketing budgets.

 As to price points, well that of course depends on your system cost. It seems pretty stupid to connect $1000 components with $1000 interconnects. Having said that, I like many of you I am sure, have heard quite modest systems, can be made to sound fantastic, with expensive accessories, so whose to know? The old rule of 10% of total budget to be spent on cable, is pretty sensible, if not followed slavishly.

Can I just say something here. There is a DIY audio/audiophile obsession with equipment, cables in particular, being a rip off which people can make in their garage far better. As aforementioned cables from JPS, Nordost, Taralabs and several others are very expensive to manufacture and have a large 'rejection rate'. How many DIY 'hit and miss' bargains do we make? likewise are any of us capable of making an 'air dialectric' or a vacuum cable? Let's also factor in the costs of holding stock, distribution, paying staff some sort of living, shows, and advertising. 
@lohanimal I think you make a great observation. It is a business and sometimes creating innovation costs money. It takes time and a lot of trial and error. Differently materials in different ways. I recently tried to replace a cable with something less expensive and I realized that the innovation of what I had to me was special sound wise. I'm not saying  you can't do well using cheaper I'm just saying that there is a lot of innovation and increased performance in the cable arena.  Some of it is costly. If you can't or don't want to try it then so be it. I just hate the us vs. them in this area. I'm happy for those who can afford it. I'm also happy for those who find great sound on the cheap. Enjoy everyone.