I regretted selling my Speccy 48k years ago, but I had to to get the money for a +2 so it wasn't that bad.
I do regret selling all my Star Wars toys though (sold them in the late 80s early 90s before the resurgence happened). Didn't have any of the boxes, but they were all in excellent nick despite having been played with constantly for about 10 years :-D
Then again, if I did still have them they'd be up in the loft making a nice home for spiders.
--edit--
I just bought another Speccy 48k a month back, ah the memories :-D