I've sold a few, most of which I don't regret because it's like JamesB said you buy a new one to fill the void.
I did sell a Red Label 12 guage a few years ago and I do deeply regret that. Most of the guns I've bought and sold can be replaced pretty easily, but a newRed Labelcost so dang much that it'll take a while to save that many pennies to buy a new one!