why do people feel the need to buy expensive cable

If you go with 'Big Name' used, the likelihood of buying way overpriced fakes goes up exponentially. Particularly big name brands and well known cables.I haven't bought a used cable in years. Just too likely to be burned. Plus the cable I really want, never seemed to be for sale anyway. If you have a local dealer who can loan you something to try, that would be ideal. Or "The Cable Company" has cables they loan out. You do pay a fee, but if you eventually buy something/anything, you get that money back as a credit toward any purchase. that way you actually get to TRY the exact cable you are interested in, or several. You can listen and decide with  actual experience of the cable in your own system.

The used high end cable market is pretty stable, so if used cables don’t work out for any reason you should have no trouble recovering your money. If you pay full price for the latest and greatest, however, it’s kind if like buying a new car. It depreciates as soon as it leaves the dealer parking lot. Besides when you buy used the cables are already broken in. 😃 it’s kind of the same philosophy that has shut down many mom and pop high end stores, such as $30,000 amps. In bad economic times like these the savvy audiophile buys used. It’s not rocket science. 🚀

Yeah, Geoff, but knowing when to buy used, vs new is critical. I enjoy high end preamps, I have found used ones as low as 25% of new retail. Last one was 30% of new retail. that means I am just leaping in on a buy I was really not specifically looking for, just because it is neat, and cheap. Works out for me so far.                  
But if I want specific cables. Like say... my seven meter Kimber XLR KS1116. Exactly how many YEARS do you think I will be waiting for one to show up used? Twenty years? Thirty?              
If you just want 'any' fancy cable and are willing to go for it, then yeah you can find good deals on cables. Aside from the chance it is a fake...

I think that’s called penny wise and pound foolish. 🤗

Get the best sounding stereo you can afford. It's perhaps one of the saner things you can do with your money. Get the best (read most comfortable, sleep inducing) bed you can afford. Give as much as you can to those organizations that promote the most public and environmental welfare.Treat yourself and other to the good things in life.
 Who knows how much longer we have? Enjoy it while it, you last.