What speakers have you mistakenly let go and then later repurchased?

Bought Paradigm Signature S4 twice. They do some things real well. 
 

Others I would consider buying again Tekton DI (although I would likely do Moabs or higher) or Guru QM2 for a smaller 2nd system , or Snell type E lll as they were musical as all get out. For the prices you can sometimes find the Snells for I would consider them being in a garage system (although they deserve better😃)

JBL 4311. 

C.S.I., the soffit or bridge mounts with 2 6" woofers

Road Doublets, owned for nearly 20 years, sold to a friend, bought back, given to son, swapped back.  Eventually replaced with Audio Physic Sitara 25's. Must have bought 6 pairs to replace the Royd's, Monitor Audio, Kef, B+W, Yamaha, even Sonab OA4's, nothing until the AP's sounded right ( they may well have been better just not right)?

Never happened to me. Looks like 2017 was a great year for jasonborne!

Martin Logan Monolith IIIx.

So frickin' cool looking.
Never really got them to sound good, but, hey... 

Sold to a guy in Japan and made money on them. So... mixed feelings.

At the moment, I don't think my Vandersteen 5 speakers are going anywhere soon.