why do people feel the need to buy expensive cable

I always look for better for less.  That often comes from, with the exception of clothes and groceries, buying a pre-owned (yes used) product. 

A couple precepts, among others, keep me out of trouble...one is that I typically have a price I will not exceed.  Second is that I always consider and understand the definition of value: "quality divided by price = value." 

In other words for products of like quality (durability, performance, appearance, etc), the one with the lowest cost represents the best value.  Everybody understands that but many don't care....or don't need to care...or don't want to care.  

Wanting something badly and being able to purchase it doesn't change it's value relative to other products.  Nor does it make it a wise purchase when overpriced and of questionable performance.

dynaquest4

.... for products of like quality (durability, performance, appearance, etc), the one with the lowest cost represents the best value. Everybody understands that ...

No, everybody doesn't understand that, and not everyone accepts your definition of "value." It's certainly fine for you to adopt this as your personal definition of value, but it's a subjective assessment, and others will differ. 

Right, cleeds, I forgot to mention that there are consumers who  blindly (or is that double-blindly) use a product's price as a measure of the product's quality.  In which case, my equation would be invalid for them.

dynaquest4

... I forgot to mention that there are consumers who  blindly (or is that double-blindly) use a product's price as a measure of the product's quality.

Your definition of value: "products of like quality (durability, performance, appearance, etc), the one with the lowest cost represents the best value" is subjective and, frankly, simplistic. It omits other elements of a purchase that could be included in assessing value.

As Oscar Wilde opined, the definition of a cynic is one who knows the price of everything and the value of nothing.

cleeds....seems like you are just in a mood to argue.  I don't have the interest or time.  For almost all purchases, my equation is accurate.  End of my participation in this issue.