What used speaker would you buy with $20,000-$35,000 and why?


I'm closer to the 20,000 part, but if I get stretched i would like to know higher recommendations. Remember, this is on the used market - not retail. I'm even interested if you think I should make a huge jump (say to 50,000), but I want to know what justifies that jump. I'd like the best bang for the buck and even the worse bang for the buck. Are there speaker lines that are totally overlooked that sound wonderful in this price range that I need to be exposed to? I may go higher, but lets start there.

PS Let's just assume the upstream equipment is adequate to drive any recommended speaker. We are not limited by upstream components.
Ag insider logo xs@2xnab2
Here's what one Orion owner said about his Linkwitz Orions on the Madisound site:

"Orion 4 Madisound/Wood ArtistryThe most important thing I can say is that this is the best loudspeaker I have ever heard in my life for reproducing natural acoustical music, regardless of price. It's not bad for electronic music either. Pretty universally excellent on rock, jazz, trance, etc., but especially good for classical music. The most natural, nonelectronic sounding human voice reproducer I've yet heard. It is dynamic, crystal clear, coherent, has thunderous and tight lows, and most especially captures in a most captivating fashion the space of a live performace in a way I've never heard from a non planar speaker, although much more dynamic and with a greater sense of ease than a planar can do. I speak being quite familiar with a variety of ribbon/planar magnetic, electrostatic, and other cone (including ceramic) speaker designs. I freaking love this speaker!"

And the LX521s sound even better.
Magico Q3,Q5 and S3 mk2 or YG Acoustics Anat Ref 2 or Joseph Pearl mk3 because they sound wonderful.

There's a pair of Joseph Audio Pearls for sale here now.  Very very rare to see for sale here.  Only $11,200.  Just buy them so I don't have to get divorced and take out a second mortgage. 
nab2     01-26-2016 10:17pm

Before I pull the trigger on this I'm fixing the room dynamics (in part by stiffening up the floor and removing the carpet). It's a near perfect cuboid, but the structure behind the walls and underneath the floor is lacking (listening room is in part of the old house).
Can you clarify what a "near perfect cuboid" is, and what its dimensions are?

Regards,
-- Al