On your example it says "price of the sheet." This site suggests "bogen" refers to the item itself, calling something similar for 1933 a "souvenir sheet." I have my doubts about it being a souvenir sheet as we, now, consider a souvenir sheet. But these sheets with reproductions may have been sold as they are.
https://www.pvoller.net/new_stamps/...souvenir.php
And I think this describes your item:
Quote:
Prior to the release of the stamps above a promotional leaflet was made available that detailed each of the new stamps. An example of that leaflet can be seen below. The sheet is inscribed "Deutsche Nothilfe - Wohlfahrtsbriefmarken 1935 | Amtliche freimarken zur Frankierung aller Postsendungen" - 'German Charity - Welfare Stamps 1935 | Official postage stamps for franking all postal items'.
(scroll down to the set, below the quoted text is a link to an image. If it does not load, you can click on it and might recognise something.
https://german-philately.com/stamps...5-stamps.php