Another point to consider is that on a site like Gunbroker, you are literally in a bidding war against the entire world.
Generally speaking only the older (usually the "mom & pop" type places) gunshops would have the older uncommon stuff, once in a while, and newer places, more focused on SALES than gun service don't want the odd, rare, or antique stuff, because it "doesn't move", and having something sit on their shelf for months or even years "costs them money", and often it is those shops putting things on gun broker.
In "ancient times" we would look for the unusual stuff at gun shows, which was somewhere the people that had them brought them out to be seen, and often sold. Anti gun hysteria was working hard to kill gun shows, and was being successful, but it was the COVID panicdemic that essentially closed the lid and nailed it shut....
They've gone away, probably for good in my part of the country. The people who used to run them quit after they were forced to shut down, venues that used to host them no longer will, and frankly the people who used to exhibit and trade can't anymore, and even if they could, there's no longer any profit in it, and damn little fun anymore.
GunStores having tables at shows were dominating them before things totally went to hell, and shows went away entirely.
This was also back in the days when you could show some ID, pay cash and go home with a gun without having to go cap in hand to an FFL during their business hours and pay for the privilege of having a STATE mandated background check run in order to exercise a Constitutionally enumerated right...
We OUGHT to be so much safer now, but from what I see in the news, we're worse off than before....