Best small used monitors under $1000

Platinum Audio Solo
A pair comes up on here from time to time under $1000 with stands(which are critical).  They are a beautiful speaker that sounds amazing.  I have the Quattro tower and absolutely love them.  

Try Vienna acoustics Hayden, incredible sound when used with a powerful amp. They're pretty close to my VA Bach and Mozart 

Wow. 22 plus different model suggestions to what I thought would be a simple answer. Tough hobby to get into! :)

In that Price Range there is nothing better than active studio monitors.

JBL LSR 305 + chord mojo + tablet/ smartphone or chord poly

option 2

Neumann KH 120 AW (white version) + Ayre codex + sotm sms100

use single solid core cables only like audioquest, dnm, vovox

get good Stands 

The Wavetouch Grand Tetons are superb and compete with virtually any speaker made - can be found used for <$1000. True "giant killers!"

Second choice would be the KEF LS50 - without question.