When I encounter situations where there's nothing in stock (at a low price), I figure it's because the store has put it back in the safe to hold until prices raise again. They probably don't want to sell at either a loss or a very nominal gain.
As far as I can tell, my primary LCS does not want to make money by holding gold and betting on it rising...while risking that the price drops further, and they have to hold onto it for months, or longer. Too much cash tied up in inventory, not making them money. That's what their customers do, not them.
They want to move it, in or out, buying or selling it, as fast as possible, so that they can
make money off of premiums, and not be at risk of fluctuating prices. They are about volume sales, in and out.
From what they have told me, when it comes to bullion coins (I can't speak to collector coins), if they hold the coins, they are not making money safely (on premiums), and they have risk of prices changing, so they have a wholesaler who purchases from them. They move sovereigns and 20 Francs fast, either to consumers, or to the wholesaler.
What they will do, is adjust premiums when prices go down. So, for the first week after a major price drop, their premiums will be higher. But, in the second week after a price drop, their premiums start to work their way to normal. As far as I can tell, they play the premium game, and the high volume game; they do not play the betting on prices game.
Regardless, even after a $100 gain, I still knew I was a buyer. Gold is not Bitcoin.