What used speakers raraely come up for sale

Lets keep it under $7,000 used, but interested to hear what used speakers rarely get listed for sale because they are so sought after and if they do appear they get snapped up very quickly?  Cheers
@ozzy A good point, made a few times. This goes for everything else as well. Enjoy ! MrD.
@ roxy54,  lol!, guess I fell for the joke at first,  Thankyou for clearing that up. 
I guess my Lawrence Audio Double Bass Speakers would make this list since they have only shipped 5 pairs to America,this info is from 3 of the 4 remaining Lawrence dealers here and also a email from Lawrence audio confirmed this.

Way cool,
Kef R107-R107/2 sell quickly in my area when priced right. Revel f series also seldom come up.