Thanks for posting that picture. I have never seen a “liberator” gun before. Very cool.
I thought so too. They were designed to be mass produced and dropped like confetti. It didn't matter if the Germans captured them, it only mattered that the population would get enough of them to kill Germans, so it produced uncertainty and loss of morale among the Germans, and it produced some dead Germans as well. It was a pretty good investment for the cost.
It gave partisans a tool to get a better gun, which they did.
They aren't terribly valuable because so many of them were made, but a lot of people who collect guns like to have one in their collection just because they are neat.