Vandersteen 2CE sig IIw are available at that price new, or much less used for the older 2CE sig. One of the real bargins in high-end. Another option is Von Schweikert VR4jrs used. The Audio Aero Prima CDP is quite good at about $1k used. Vandersteen house sound is more laid back but very, very good, non-fatiguing sound. VS 4JR more up-front; maybe more rock or big band oriented.
Or how about Merlin VSMs (older model, used); ARS Sonum tube integrated (used) and the Audio Aero Prima. That should come in right about that $6k budget and the speakers can be upgraded over time.
Or how about Merlin VSMs (older model, used); ARS Sonum tube integrated (used) and the Audio Aero Prima. That should come in right about that $6k budget and the speakers can be upgraded over time.