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.
11-26-15: Maplegrovemusic
you guys are still equating price to quality , or being good ? It is fine to live in a fantasy land . Those of us in reality realize price and fancy jackets do not provide sound . The natural elements of the earth inside the cable do. So why charge someone a ridiculous amount for these elements ?

More materials, cost more and there is more opportunity for mark up. No one disagrees with that. It has also been my experience in my room that the fancy jackets/layering does have an "affect" on the sound depending on the application. Here is a personal example of this

In this picture are two of my

personal phono cables

The one on the left is a custom loom made for me, to my specs.
The one on the right is my Purist Audio Venustas cable.
The Purist Audio cable costs 5-6 times as much (maybe more now - 8^0 - as my custom loom, and it is used with the stock wiring that comes with a tonearm.
Connects to the back of it for those not into vinyl here.
My custom loom is a straight shot. The custom loom plays in a different league in my room. More immediacy, bigger pipe of sound, blah, blah, blah....
Now if I was wire crazy I could have 5 or 6 custom looms made up with different wire types to match the cost of one Purist Audio Venustas.
The tonearm's design allows for changing out this loom in 10-15 minutes.
"Typically you ended up with the money because you were smart enough to put yourself in a position to even have a system and afford the hobby."

Something tells me you don't live in the US. Over here, typically someone does go out and work for the money. Quite often, though, someone else ends up with it.
If one has settled on on a single core, solid cable (which I have) then there's not much that can be done that others have. Get a good enough purity, use bare ends, anneal it a few times, even cryo it, and the only variable left will be which gauge to use along with which sheathing works best for you.

As much as I love the sound of some multi-strands (Supra Ply and Zu Mission) and the lovely, melodic presentation they are capable of, they tend to only capture about 80-85% of the extension and air of solid core. They capture probably best, the sound of a live event, to a point. Some detail is missing along with the air and extension mentioned but if that's all I had on hand, I could happily live with them. But I like the detail, tone, texture, extension, definition and presence of single, solid core. There is no glare, hype or etch, just a much better focus and clarity.

Having said that, I know there must be some brands of stranded out there that close the gap on solid core and all the R&D and material needed to justify the cost but in the context of my system, single, solid core gives a mighty fine, dare I say, excellent, acquittal of what is possible, desirable, and satisfying.

It's all system dependent.

All the best,