I'm sure I would extensively explore used speakers over at Audiogon and other places. For $10K, odds are that you could get speakers in very good condition that originally listed for $20K-$25K.
Personally I would be on the lookout for speakers from Von Schweikert, Sonus Faber, Vienna Acoustics, Dunlavy (or check to see if AudioLogic was still clearing some out), Aerial, Alon, JM Labs, and maybe some Vandersteen 5's if some showed up. I'd recommend adding Thiel to the mix as a line to check out. And certainly Martin-Logan and Magnaplaner if you like "panels." Lots of other good lines out there too, like Tannoy, B&W, ProAc, and so on.
I purchased Von Schweikert myself and there are almost always some excellent deals on used VS's. Can be tricky to find a matching center if you go back to the original line.
If buying new, I would still consider most of the lines above - but now I'd be looking down a model or two in each line because I would have to pay 80-90% of list. And would add VMPS and ACI.
There are many, many good speakers at this price point. Very hard to sort through them all, and what makes the hair stand up on the back of my neck might leave you cold.
Tom B.