Higher price being indicative of demand, the answer could be several things. It could be that the supply is more limited. Or, it could be that the notoriety of the entity behind the military collectibles and memorabilia is driving higher demand somehow, despite supply not being more limited.
I suspect supply is not more limited by comparison in the instance of military collectibles and memorabilia from Nazi era Germany. They did understand the usefulness of good design and definitely put it to work for them, for propaganda purposes I suppose. Then, there’s the forbidden fruit aspect, it’s a little creepy therefore more people find it desirable in a perverse way.
Confederate collectibles and memorabilia I suspect are limited in supply in comparison to Union. There’s the whole lost cause thing and a degree of romanticization, there’s a somewhat captive audience in the descendants of Confederate soldiers wanting specific items, and then there’s a great deal of historic international interest as well. There was more variability and visual interest among the various states of the Confederacy in comparison to Union states, so there’s that. The Confederates were the exception rather than the rule and represent a way of life that has largely vanished. It’s more valued than what are essentially just old US military items for these reasons.
Bttt