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

While I like to hear how other people combine amplifiers and speakers, Magnepans closed my mind to anything else.

Preowned Wilson speakers are VERY common to see being sold very much including the most expensive production models (XLFs as you read this on AG & virtually everything else) - however in all the decades the WAMM has been made, I've never seen a single one come up for sale.  All 7 versions (not including the Chronosonic which is arguably too new).  Something peculiar there.

Technics SB E200.  

Getting ready to sell my Aerial 8s for Martin Logan ESL 13A.
Made 70 on 3/10/2019, with hearing loss...”dying” to make one more change before I hear the trumpets call. Am I making a mistake ?

GOOD ONES.