What do $2500 speaker cables sound like?

Halve your budget, buy some Silversmith Fidelium SCs, and find out.

Op, Do you really want to know?  A $2,500 dollar cable will sound like a $25 cable, or a $100 cable, or a $99 cable, or a $20,000 cable or a $49 cable, or a $199 cable if you let your ears decide. If you let your eyes decide I expect a much more linear as opposed to random relationship.

Look at the system pages of most of the people advocating cables. What percentage of them have really well implemented acoustics? Aren't these people the self claimed cream of the audiophile crop?

Everything variable that matters in a cable for how we are using it can be implemented and controlled inexpensively. 

Do you have a limited even if extensive budget? This is not where you are going to make a difference.

Your best bet is finding loaner cables or purchasing with a no hassle return policy.

Otherwise it's a yes,no and maybe Merry go round.

I have 3 speaker cables.

1) Benchmark cables with SpeakON connector ($150)
2) Audience Conductor SE (I think $1K)
3) Audience FrontRow with SpeakON connectors (around $3.5K)

The first 2 are very good for the price and when I use them I do not feel like I am missing out.

However, when I put in the FrontRow in the floor standing system I heard more detail and more clarity. Improvement on an already good sound.

Now the place where I really notice the greatness of the FrontRow wire is when I put them with my Benchmark AHB2 amps to drive my RAAL SR1a headphones. With the other cables I noticed a bit of hardness and had some fatigue via the headphones. With the FrontRow the hardness went away as did the fatigue. So I have crazy expensive speaker cable for my headphones. With my floor standers it was not needed as much as with the headphones.

I cannot think of anything as more revealing than the RAAL SR1a so it makes sense that the FrontRow made a difference.

"...What do $2500 speaker cables sound like?..."

Cables are qualified by their sound qualities not their price. If you think $2500 is a lot of money for a cable you probably aren't going to buy it, so it's a moot point anyway.