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

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.

Vandersteen 2ce Signature (II or III; can't remember which). I let them go in 1990 because I was going back to school and couldn't fit them in a dorm room. They were the first speakers I ever owned that hung a solid, deep, tall image in front of me and sounded good with either chamber music or The Chambers Brothers. So when I got out of school and had room once again...

Bose 901's

Never sold a a pair.  However, I have upgraded with three successive pairs of

Magnepans.  Love them all.