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

Vienna acoustics Beethoven, I tried many speakers that could go louder or had harder driving bass, even the VA Strauss didn't have the mids and top end of the beethovens. Now they're serving ht duties in my tv room, but upgrading from them cost a small fortune.

Like mglik, I bought my first pair of the old Quads in the late 80s. Sold them when Quad announced they would no longer provide parts for the 57s. Bought my second pair in the early 2000s and kept them for about 8 years. Just bought my third pair and this set I will hold on to forever (I'm a slow learner). The Quad ESL is not perfect, but it's the closest thing to perfection that I have heard in my home.  

Merlin Music Systems VSM...

I never sold a pair and later wshed I had kept them.

I just kept the ones I really bonded with. Still own (and use) Energy Reference Connoisseur, Martin Logan CLS, Vandersteen 4A, and Wilson Maxx 2

I have also never regretted selling off a pair of speakers, even if I enjoyed them at the time. I kept moving up, and carefully.

I did enjoy an old McCormack DNA-1 power amp (and a 0.5 too) but let them go only to eventually re-buy another DNA-1 (cheaply/lucky on eBay) which is a rock-solid and nice sounding back-up amp for many speakers.     That's it.