I'm developing a world where governments are freaking out over a perceived threat (not a virus). The stars have disappeared and the gods have seemingly abandoned them. Many leaders have ordered their borders locked down and trade routes closed for various reasons.
Different countries would have the resources they can produce themselves (obviously) but things from outside would be increasingly scarce as time goes on. I know that not having shipments to a desert country would raise the price of the remaining wood products in their markets. But I don't know how much. I know what each country produces and what they import.
My question: What is a reasonable scale for increasing scarcity?
I'm mostly looking for a realistic percentage I can add to market prices every week/month to reflect the scarcity. But if a set scale is more realistic let me know.
P.S. I know my PCs will be able to exploit this with smuggling and get "hella rich" as they would put it. But in the long run if they waste their time smuggling they will come to the inevitable end of the campaign with too much money and not enough power. I'm letting them know it's on a timeline so they can make their own decisions.