I probably most regret selling my CSPPC on eBay a few years back, it wasn't a great sale either as the buyer messaged a couple of weeks later to complain the card was "dusty" and sometimes crashed his 4000. He claimed his "friend" fixed them and he wanted to renegotiate the price to 200EUR, so when I refused he returned the card but it was in fact completely dead, I later found out it had been reworked, probably used as a donor card to fix another and was completely unsalvageable.
My other regret was several years ago selling my AmigaOne XE which I was planning on replacing for a newer NG machine running OS 4.2, but as that never materialized I eventually lost interest. I coincidentally enough noticed it for sale again on eBay about a week ago, my hand was hovering over the buy button, but as the seller was looking double the price I decided the money would be better spent on restoring my A4000T which I'm currently working on.
https://www.ebay.co.uk/itm/Commodore-Amiga-One-amigaone-g4-full-option-/332624900763?hash=item4d71fd329b%3Ag%3AmnkAAOSwN3Na139q&nma=true&si=I3cuxAsa9jsHoYjEV6tbsfFjxr0%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557
