The Sophias are an excellent speaker and a good value. However, I can think of no better speaker for the classical genre than the Harbeth Monitor 40. These are rarely available used but will set you back a lot less than a pair of Sophias--and will perform better. If you can stand their appearance (huge boxes) then this would be my top recommendation. Cheaper used and similar (but less revealing) are the Spendor SP100. I had a pair a while back--excellent speaker, one of the best I've owned. You might even consider the Harbeth Super HL5 which is a phenomenal value and can be gotten used for around 2.5K. It is less full range than the Monitor 40 but you won't miss much on the bottom and the coherence and instrumental timbres are faithfully revealed. I know that each of these recommendations are considerably below the 10K price point you set but I really don't think you can do better for classical music regardless of the money--why not put the balance into upgrading source and electronics?
Best speakers for Classical music under 10k used
I currently have an upgraded pair of Thiel 2.3's that I have been happy with but am now ready to upgrade. I plan on listening to the Thiel 7.2 and the Wilson Sophias. I was wondering what others I should seach out? For 'classical' music only - big orchestra to solo instrument