Have you heard the Maggie 20.1s or Soundlabs? Soundlabs should have at least 2 models in that price range.
There are some things they do that are almost impossible to match with box speakers, though of course box speakers compare much more favourably in your price range than at less. But before spending this much - you've got to at least hear the Maggie 20.1s (with proper amps) to know how they are different/similar.
Oh - and if you aren't sensitive to sweet spot size (I am) then these might be interesting:
http://www.sanderssoundsystems.com/10b.htm
I've heard some of his older speakers and they do seem to outresolve every other electrostatic I've heard... That is pretty tough to do!
But main thing is to listen to 20.1s and see what you think - if you are intrigued then check out some SoundLabs and the Sanders ones as well.