why do people feel the need to buy expensive cable

Some cable sound similar.  Some much more different.  How much usually varies case by case for many reasons.

The devil is always in the details.   it helps to avoid generalizations that do not always apply.

The best way for this for this thread to go away is not participating, a audio builder will try anything that has his interest,  sure,  some are decision failure's,, some are are satisfactory, and of course,  there is the wow factor,  that said,  the real perspective is that the  general public think's an audiophile is obsessive, wasteful of money,  down right crazy for the amount of money north of $1,000.00 for an entire system,  this thread has no constructive learning,  although I am certainly a believer of good  cable's can work to benefit a system,  my reason for this post is to persuade respectable audiogon member's that this thread is like discussing politic's, a never ending debate that by the end of the day,  accomplished nothing. 

It allows us to release the inner angst we all harbor and enables us to validate ourselves in an anonymous consequence free environment!  Now that's worthwhile....carry on!

Sometimes you get what you pay for with regard to quality. Sometimes the dollar cost and spent amount is low and you receive an outstanding product. Other times you can pay extremely high prices and get something that leaves much to be desired with quality. Having watched cables being made by someone that knows what they are doing, using components, materials and a honed set of skills you can achieve an excellent set of interconnects and power cables for a very reasonable sum that is in the realm of the working world.

If we are talking just wire, then there are many values.  On the other hand, MIT can not be duplicated and Transparent has a unique design as well....both offer more than just conventional performance.  There is no short cut to what they do and their is no value alternative.  So, as long as you have convinced yourself that MIT AND TRANSPARENT aren't for you....many wires exist and your results will vary.  For me MIT delivers a whole other level of realistic audio playback that no other cable delivers.