What do $2500 speaker cables sound like?

I tell my kids to experiment and evaluate.    You should do the same.    Grain of salt with some of the AG folks that tell you otherwise. Do your own due diligence.

For me after many years, good conductors, good connectors (or no connectors), secure connections, provide the best listening experiences.  

That is easily achievable much much less than $2500.

The whole notion of cables "getting out of the way"...or, having neutral or "no sound signature of their own" is ridiculous. 

I’ve never heard my system without speaker cables or interconnects. Have you?

As cables get shorter and shorter, their effect upon the system reduces linearly.

Hence I would be more likely to use two mono block or two stereo amp servicing the bi-wire inputs behind each speaker and a short zip cord, than spending 2500 on a cable.
Assuming that one can get another amp for $2500 or less. 

Some cable risers I made many moons ago from bowl blanks. Just modified them to accommodate the Fideliums. Have lead in the bottom for more stability. These really help to keep your routing neat and tidy. I have no need to run power cables through these to keep them off the floor as well with this new set-up.

In use

Better cables make a diff but market is grossly overpriced.  Competition not taking hold to reduce prices,  why ???