Only one I regret selling was a BHP, used the funds to buy a Gold Cup.
I have bought and sold a lot as a result of thinking it was something I wanted.
Case in point, I have always liked single action revolvers but every time I get the bug I wind up selling it soon after purchase, at least this has been the case with four Rugers. Just can't get comfortable with the plow handle grip and long hammer throw. Last one I ordered was a Blackhawk Bisley hunter, imagine my disappointment when it arrived with a plow handle grip, traded it three months later for a Smith 625 and have never regretted it. Still get the bug once in a while especially since Colt has revived the New frontier.
Other than that I traded a Berretta 96F for a Sig 229 because the Berretta couldn't group, for me, worth a damn and a Walther PPKs because the magazine kept falling out and the trigger was terrible.
To a man with only a hammer everything looks like a nail.