Most of the guns I sold, there were good reasons (other than only financial need), so while I may sometimes wish I still had them, I don't really regret the sale. There a few guns I truly regret and one or two more I wish I kept, but it isn't that big a deal.
I most regret selling my .40S&W SIG P229. It was a great gun, but I needed the money. I am a teacher, and where I used to work didn't pay us over the summer, and due to some unexpected expenses, I didn't have enough to get through the summer so I sold one my favorite guns because it was worth the most and I needed to pay bills.
I regret my CZ 40B, I didn't love .40S&W yet so I sold it and they have been out of production and nearly impossible to find and replace for years. I sold a S&W 57 from the first year of production because it was so hard (and expensive) to find .41mag ammo (why didn't I just start reloading the caliber
).
The last one, it isn't so much the gun (a Taurus 82), nothing wrong with it, but it was a pretty plain-Jane medium frame .38spl with no particular history or pedigree. It will be easy to replace. However, it was my first handgun and I got rid of it for a stupid reason. I figured I'd only own a small number of guns: a couple rifles, a shotgun, one revolver, and one pistol. When I bought the .357mag I really wanted and a 1911 the revolver and pistol I already had were to be sold because I only
needed one of each. Now, I really wish I still had my first handgun, and I have a lot more than one revolver and one pistol.