One of the modules that I sold with good reason, I felt nostalgic about later and bought a second one… and then I didn’t love it and sold it again.
With another, I sold it, missed it a while later, acquired another one – and the knobs are physically better, so I’m happier with the second one 
With another, I used to love it, found myself not really using it, sold it. Then a newer revision came out, and I bought that. It’s good, but it’s not getting a lot of love right now. I’m going to give it a fair chance in the new environment I’m setting up.
And I sold my original Ornament & Crime, but bought a uO_C later in order to use Hemisphere Suite. It suits me a lot better and feels like a completely different module.
There are times when I think “I should have kept my DPLPG” but I’m okay without it (I do have a Natural Gate!). And I think now that it might be fun to play with Synchrodyne and the Doepfer BBD – but Synchrodyne was an expensive, often awkward, weird module that I had a hard time fitting into my music.
So, no regrets here either. 