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

I have entertained the Magnepan's. I'd like to set them up A/B in my room with my speakers. 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).

Only downside of shows is that it's all cutting edge stuff not used stuff like I'm asking about here. A slightly used high end car generally drives pretty close to a new one at a fraction of the price. Electronic gear is even closer due to the nature of electronic components.

I'd say in most cases, especially ss amps and preamps that holds very true......speakers are all over the map, there's a 30K pair of Martens on GON for 12900......will they beat a pair of Mag 20's in most categories?  no.......so does that mean they're overpriced?  who's to say.......most would say new Maggies are severely underpriced........

So what do you get with Maggies that others can't touch:

There's a definite sense of space around instruments that create an eerie realness and it's primarily a function not only of speed, but also dipole dispersion that's close to perfect.....instruments on a stage create a lot of their image by reflecting off the back wall as well as directly and dynamic speakers with a few exceptions just don't reach that element.....

The downside has always been the low end, but the 20.7s pretty much negate even that argument if you feed them what they want, which is a lot of SS watts with high current, coupled with a great tube preamp......

I've owned 30K speakers......I now own 6K speakers......

Give them a chance if you can deal with their size......they're very forgiving in terms of placement.......some listeners even listen to them with the edge of the panel facing them.......LOL

I would try some Grado PS1000e headphones for a paltry $1,700 and see if they satisfy your musical needs. Amazing sound there, IMHO.

If we are going that route we should do LSD or shrooms...

I wouldn't recommend that, based on personal experience. The last time I tried that stuff, an orange rhino walked into my condo from the patio and started berating my modest Ax-7e/P3esr setup, and boasted on how his McIntosh system was SO MUCH BETTER...  :-)

In terms of the thread, if I'm spending my own money I would look at Harbeth 30.2 or Magnepan 3.7i, and bank the rest.

If I'm spending your money, I'd look at either Wilson Max-3 or Tannoy Westminster Royale SE.

FWIW, if it were my money, I would buy a used pair of Sonus Faber or B&W speakers. I'd buy as high in the line (used) as I could for my $20,000.
You won't regret it!