why do people feel the need to buy expensive cable

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.

You have to see what a system can do first and that's down to the details. Placement, the room, speaker stands, cabling, power. All these things can sometimes make a system sound ten times better than it did because they were overlooked.

Of those things mentioned by pokee1016, cables are least likely to make an improvement is audio quality...assuming good quality (proper length and resistance) cables are already being used.  Basic, good quality cables are not expensive.

I agree that most cables are of a similar design and can be had fairly inexpensively.  However, Transparent and MIT cables are demonstrably superior at creating a lifelike reproduction of the music.  They offer a broad range of products for both the audiophile on a budget to the no holds barred crowd!   Choices are great these days, solutions abound for all types of audio enthusiasts...enjoy and stop arguing over which is thee best for everyone.