How much is my Kathe Kollwitz print worth?

It is a print of "The End" or "Ende," from the Weavers. There is an imprint in the lower right hand corner that reads "A.V.D. Beck Muenster 22." There are no other markings anywhere on the print, or on the back of the print. I also have a Kollwitz self portrait with the same imprint in the same spot, but I don't the title of this one. How do I find out if this is a reprint or a restrike or anything? Where can I go? I know nothing about this sort of thing, they were simply a gift. Thanks for any help you may have!