What are the speakers you very rarely find in the Used market(Audiogon or Anywhere)?

Windmilldad: I own ML 13a. (I can speak from experience having been an audiophile for 5 decades.) They were very good speakers when matched with reputable amps and preamps. A year ago I took it to the next level and went with Don Sachs tube preamp and Krell’s 575 XD mono. Now they’re a great speaker, I can’t imagine better SQ. Two important items when working with the 13a, the amp needs plenty of power and the preamp should be tubes. Enjoy. 

The be-20 dmd’s Are excellent speakers and I have a pair of them along with a pair of DSP8000’s and I have to pick 1 to keep, you would think that the $65k speakers would trounce the $20k ushers and I wish it was that easy but those big ushers have a lot going for them and when we factor dollars per smiles the usher speakers are a bargain.

Add another ditto for Aerial Acoustics.

I've never seen a pair of Vandersteen 7 Mk. II and rarely see 5a Carbons on the used market.

Audio Machina.