Back when I was very active with gunshows, I bought, traded, and sold quite a few things as part of the hobby/interest. Looking back today, I sold some stuff that later grew in value significantly, but at the time, I had no regrets. Selling or trading something off as part of the hobby was part of the plan. I sold off some really nice and collectable stuff. It was fun.
If I had it to do over again, I would have cherry picked a few 38spl Diamondbacks and Pythons to keep as "investments" and round out my accumulation and be more flexible on conditon especially on older stuff. But I really have no regrets. Hindsight is 20-20 and my crystal ball was never that good, so I bought what I liked and didn't worry about what the future held in store in terms of values. And guess what? I still like what I ended up keeping around.