Curious what people think is the best "value" high end speaker (~5K to 15K)

I recently wrote a review of 15 speakers, most in your target price area:
https://forum.audiogon.com/discussions/a-brief-review-of-15-high-end-speakers-on-home-demo-including...

I would not agree with whoever said the B&W diamond tweeter is harsh: it is smooth as silk. I heard the 802D at a recent Hi-Fi show and it was the best at the show - a full, rich, natural sound. And great value at present due to the depreciation of sterling. I have a pair of 804D in my second system - but I would not recommend them for the size of your space as the sound is a little bass-shy in a big room.   The 802D is a different beast though. 

I agree with the Joseph recommendation. I heard them at the Munich hi-end show - fabulous sound.

After trying out 15 speakers, mostly on home demo, and with a budget similar to the top-end of yours, I ended up with Boenicke speakers - a mighty full and spacious sound from a relatively small cabinet. The W11 or W13 would work well given your room size. They have a beautiful way of delivering music, and they are incredibly musical. They render a tube-like quality to a SS amp. Also the speakers can be sited more widely than many, if you so desire, giving a very broad sweet spot, which may appeal to your circumstances.

To answer your question, I recommended the JA Perspectives because they have a small footprint and a wide dispersion pattern that stays fairly uniform off axis, which is why I think they continue to sound good outside the sweet spot. 

Are there other speaker characteristics that are important to you other than those you already mentioned?  If so that would be helpful to know, along with what type of amplifier you're planning to use if you have any preferences. 

Aerial 20T V2

MAGICO A3 great sound great price only $9800.00 a bargain jump on a pair asap.

Another vote for Tekton here. The Double Impact SE's or Encores would fill your room with wall to wall sound. My DI SE's disappear completely, are seamless from top to bottom with beautiful tone and texture, impressive dynamics and delicate detail. Yeah, I guess you could say I like them!

I've owned Vandersteens, Magnepan, Revels and Legacys.....all great speakers that I enjoyed immensely.....but my Tekton DI SE's have brought me the most musical enjoyment. Good luck in your search.