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

Good!

A lot of good speaker recommendations have been offered, which would be suitable for a room of that size (assuming, in some cases, that the structural improvements you are intending to make would enable several hundred pounds per speaker to be comfortably supported).

In addition to the speakers that have been mentioned, you might want to consider some of the models from Sound Lab. One of their dealers, btw, (for the Rocky Mountain region) is Duke Lejeune of Audio Kinesis, who participates here from time to time as member Audiokinesis, and who is by all accounts a wonderful and very knowledgeable person to deal with.

Disclaimer: I have no personal experience with Sound Lab speakers, but if I were shopping in your price range, and had a room of your size, based on what I know of them they would be high on my short list.

Good luck. Regards,
-- Al

None, the better bang for the buck is to go surround 5 speaker setup with cheaper speakers. It’ll sound better too.

Agree with Stringreen.  Have you ever seen anyone list an ad for someone selling a Vandersteen Model 7?  Must be a lot of happy owners...

I agree with the poster that you should head to one of the audio shows to hear many expensive speakers, which is the rule at such shows.  However, in my experience, and I have had a number of really expensive speakers, you should try some of the single-driver speakers.  I bought a pair of Audio Nirvana 12 inch alnico drivers and mounted them in a 5.6 liter cabinet (I also had some 8 inchers in a 2.8 liter cabinet).  These cost me about $1500 and I will never (as much as any of us audio nerds can say never) go back to multi-driver speakers with electronic crossovers.  Just a thought before you did like I did and spend a lot of money chasing what to me doesn't sound like live music.  My kids and wife all play musical instruments.  An added bonus is that these things are really easy to drive due to high sensitivity and a more resistive load.