What does one purchase after owning horns?

The best speakers I ever owned for piano, in particular, were my Apogee Full Range Planars. They have the added benefit of providing a true 25Hz to 25kHz response. But they are big (over 6' tall) and require a small power generating station as a source - well, about 200W x 4 of good old-fashioned SS power at a minimum. A used pair of Duettas or Scintillas would be within your budget, are a little smaller and area little (very little) easier on the power requirements as well. Note - these speakers have about the lowest WAF rating of any speaker ever made, exceeding even the Avantegarde in this respect.

The used pair of Magnepan 20.1s will get you in the same ballpark as the Apogees, less the bass response of course. But I don't know if you can do it for $8K. Maybe a pair of 3.7s and a sub?

1 question, 34 opinions (including mine, of course). I love this hobby!

Horns can work well in smaller rooms too, if you take care to carefully match the amp and speakers. I have used Belles in a room 10 x 12.5, and also Altec Lansing Model 14s in the same room. Works great, and may require less in the way of room treatments then conventional speakers.