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

If you have the room for them, forget the used journey
and get Magnepan 20.7s and apply the difference
to your source and amplification chain.......around 13K
90% of the way to the 20.7s are the 3.7i's at around 6K

You can attempt to do better, but you won't..........

I also cast a vote for the Linkwitz 521, but the multichannel
discrete aspect makes it a difficult speaker.....plus you have
to build it yourself.......

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