Glad you emphasized that important type of logical fallacy. I often see it as the "Simple and inexpensive cables are not good enough, therefore you need the exotic cables that look very impressive. (And by the way you need this cable display device also, so everyone can enjoy being impressed.) Couldn't resist throwing that last part in, since it would be a shame if the expensive cables not prominantly displayed.
As we might put it using the word "diddly" as above, "It DOESN'T mean diddly what your wire is made of, therefore you need the very expensive type of cable or interconnect." It is the simple Fallacy of Exclusion. Another example: "Zip cord performs extremely poorly in my system, therefore my cables must be as different from zip cord as the day is long, because I am an audiophile!" Yet this proposition, "zip cord performs extremely poorly in my system" does not mean that you can't make excellent speaker cable USING zip cord and other non-glamorous parts.
A good inductive inference gives us a reason to believe that the
conclusion is probably true, and therefore we should spend all that money.
It seems to me that invariably, someone has cables that cost more than at least one of the components that generates or amplifies or outputs the signal! Yet no seems to buy cables that cost more than each component! And from what I have read, cable ownership decisions seem to always be influenced by free samples or wholesale cable purchases.
And post hoc ergo propter hoc , "after this therefore because of this" is another possible fallacy we should not fall into. For example, did you try those amazing cables on a piece of crap system to see if it made a difference!
Also we can't forget the JOINT EFFECT part of post hoc ergo propter hoc
disclaimer: This is not a full argument against outrageously priced cables. Cable testing has to be as hard as any a-b(-c) testing. This does not mean that cable Y doesn't sound best to someone in a system with components a,b,c,d,e,and f. But such tests don't tell us WHY cable Y is sounding good, or if it will sound good with a system with components p,q,r, and z. Notice my avatar - a flame suit.