Never thought of keeping or selling as a "policy" issue, so I'm coming into the discussion a little indifferent.
My first gun was a Daisy Red Ryder. I wore that thing out so it could hardly push the BBs out the barrel, that is, unless I tilted the rifle and it simply rolled out. Many moves later, it just wasn't there, anymore. The next was a Diana, break action. Shot that thing loose all over, and half the screws were ill-fitting replacements, by the time it was all over. More moves, and it too, was gone.
Perhaps I'm missing something, but I see firearms, like cars, as toys or tools. None of mine were heirlooms, where I was simply a custodian, waiting to pass it on to the next generation. Even then, the unavoidable medical bills, and yes, tuition, even bail, would have taken precedence. I would value health, homes and relationships over them.
I consider those who never had to make a choice incredibly rich,....or lucky. Never say "never".