New or used speakers

I should add I listen to primarily rock and prog rock.  Not heavy like the laid back and soft tunes. About 70-80db on loudness.  

I have found that speaker performance within a segment largely depends on cost. So, I have always found that investing in one set of speakers (like trade in and upgrade) always allowed my system the highest performance level. Of course, different people have different objectives. 

If I were looking within your budget,I would probably want to check out Joseph Audio.   

Used . 

Used for sure. You'll save so much.

Definitely used. 

Replacement or a second set? Why not talk to Ty? Upgrade the tweeters to the high resolution Scanspeak, upgrade crossover, and add a pair of REL T9x subs.

What is your goal? More bass? 4 Speakers rather than just,2 ? 

My room is bigger than yours and I have faced the same issues. I also listen mostly to classic rock and blues. And I have struggled with upper midrange glare.

My system was improved greatly by 2 subs. Now it sounds very good. I agree with @noromance concerning the pair of Rel subs. But I would go with the S series with a 12 inch woofer which is what I have.. 

@noromance I like Ty's speakers. They have upgraded Seas millennium tweeters and upgraded crossover on the bass also. My wife says to get a second set for this room as I put my Kef R11 in the den. Forgot to mention I also have 2 SVS SB3000 subs. @artemus_5  the sound is a little lacking sometimes in bass at low volume. But when the recording has the bass it is thunderous. Pink Floyd Sorrow sounds like the house could fall down. I was just wondering what else would match with my system well. I was thinking maybe  Tannoy Arden. I know I don't like the horn on a Klipsch. 

If you're starting from scratch and want to build a system around your new speakers then buy them new and enjoy the experience. Fitting speakers into an existing system is trickier and I personally buy used first at prices I believe I can resell at little loss. Once you find the sound you like you can still resell and buy new in the finish you want.

Yes used or demos. I have had good luck buying demos for my last two speakers. Saved about 40% on 99% new speakers. 
 

I think the key or buying used/demos is having 3 or 4 speakers you would be happy with abs jumping on them when they come up local. Also not being picky on color helps too. 

$10k used=up to $20K new. 

Of course, that price depends on condition, age and negotiation skills.

No shortage of great speaker listings. You're in the drivers seat with cash, be picky.

Used speakers like used cars give the best value.

myself look for very good speakers with quality drivers ,then I totally upgrade the wiring and Xover parts the biggest  weak point in all speakers including ones at even $30k+ are not much betterthen average parts ,like Mundorf Evo capacitors  ,decent but not even Mundorf Supreme quality  , Never mind World class brands like Duelund    put $1300 + into a Xover and it’s like buying a speaker 2x + the cost .

You don't have to spend anywhere near $10K to acquire great used speakers.    The compromise is that you might have to accept that the speakers were manufactured by a company that no longer exists.    If the speakers are good, you can usually find someone that knows how to rebuild them, if the need ever arises. 

How about ADS?    IMO, they included the best domed mid-range ever designed.  Take a chance....