Are Expensive Balanced Interconnects Necessary?

my short answer is sometimes, but generally not nearly as important (as unbalanced rca ic’s)

btw, nothing in high end audio is necessary, the entire hobby is not necessary -- to have the means and desire play with any and all of this is a luxury in life

yes

I've been using balanced cables in pro audio applications for decades, and when recording the audio for a TV show some years ago I swapped out some pedestrian cables for a set of new "expensive" balanced cables. Immediately heard an improvement (good headphones tied into the mixing board...live feed...you can hear the musician's heart beating). Mo bettah sounds mo bettah, and dats dat.

Most people can't help arguing balanced vs unbalanced even if the question is something else. 

My answer to the original question is that moving very far up the manufacturers line in either balanced or unbalanced provides limited or no returns but that both types of connectors benefit from good wire, good connnections, and good connectors so don't go with amazon cables.  

Cables do sound different, even in xlr configuration, it is up to you and the system if necessary.