Do Costly XLR Cables Make A Difference?

Most are easily separated from their $$$ when they perceive an improvement, enjoyment and satisfaction from the purchase.  This is true in everything we buy.

If you don't see, hear, taste  or feel the improvement, then you are most welcome to keep your money.  Especially if that gives you satisfaction!  People come here to see if others have appreciated all the various upgrades vs. others that have not experienced them.

Good expensive cables if  match properly the cheaper even if match , the expensive one win.

have said this in many cable threads

for dedicated audiophiles who sometimes change their equipment, it is good to treat a selection of cables as tools in a tool kit for final tuning, as they can and do subtly alter the sonic presentation, in terms of frequency response, perceived speed, openness, imaging qualities -- this is due to physics, different cables of different materials, construction, connectors, represent different electrical properties (r-l-c) and isolation from the surrounding elements

cost of cables is another matter, there is much marketing b-s, especially regarding hyper expensive cables... so long as the cables are well made, with quality materials and terminations, it is smart to know what cables do what sonically, one can use cables to get the synergistic effect desired at any given time

in my case, i have been at this for many years, swap equipment quite a bit

so for interconnects i have beldens cardas zu discovery cerious to smooth/warm the sound, kimbers nordosts nbs to liven things up up top, vampire and other shielded silver cables to get more vast open imaging with a subtle sheen, straightwire wireworld mogami and midgrade audioquest to start things pretty neutral when a new component is inserted, go from there, and so on...

there are those who say cables shouldn’t used a tone controls, in theory yes, but as a practical matter, experienced hobbyists do this regularly

Try Vogue Audio pure Silver Cable's, they're inexpensive and very good quality cable's.  They are my go to online store for XLR Interconnects, Power, and Speaker Cables, oh yea, RCA Interconnects. 

“…for dedicated audiophiles who sometimes change their equipment, it is good to treat a selection of cables as tools in a tool kit for final tuning.”

@jjss49 

I agree, and with the rest of your post too.  
The cables need not be expensive but it helps if they are different and bring their own unique strengths.  For example, I keep SCs by Harmonic Tech (lots of OCC copper, fine gauge solid core, and individually insulated), Furutech (super fine strands of OCC copper in foamed PE), and NOS WE (annealed, tinned, stranded copper), and a few others that all result in a subtly different sound.  Same type of deal with PCs and ICs.