Everyone of us know WWII and dark period of German Occupation - personally, I never collected this material, specially I don't like to promote any material that can glorify in any way German atrocities and destruction that they made at the time. Here is just one section from web that say: "... Nazis made Ante Pavelic head of the NDH. His Ustase Storm Troopers began eliminating the two million Serbs, Jews, and Gypsies in the NDH...".
But when it come to Philately, I see that some of stamp, issued at the time of WWII have "classic" design and quality work done! Here, one sample from recently obtained collection, that - when I discovered it inside pile of album, say just "Diamond" - and yes, it is one "must be" item for any more advanced collection that You can build.
Lets start with statistic, which will say, Mi Bl. 8, P. S. catalog no.: 8, Scott B76 s/s, comparing this three major catalog, we come across very big difference in description and prices, probably it is because West and European market difference, and probably something "other" are in the game.
To mention, that this block is issued on Jan. 9, 1945 (Scott have it just under 1944 year), even with date/year of issue this two catalog have difference. This block is issued with intention to promote Croatian division that was involved in many battle over Yugoslavia and abroad, and surtax go directly to finance this "Storm Division". What we have in quantity printed is 7500 sets and 2500 s/s - which is too low for time, and topic! Don't forget, that after WWII come to power communist, which well know how to erase any fascist symbols or "propaganda" of any kind.
Next one point to suggest: Be very careful when purchasing this items, don't do it from any web auction, and if You have it, go and made certificate for same. Even that I can not say who is right, but Scott stated that "plentiful counterfeits existed", Michel catalog don't have this "mark" and PS catalog clearly stated that expertise are need, because "many fake existed, that was produced using ORIGINAL ofset plate". This material You buy JUST and JUST from certified dealer, personal dealer or someone who You personally trust.
Now, what say market? I see that it is nice investment material to obtain - prices from "year-to-year" go up, not because inflation, but because demand, and if it have in 2007 catalog price tag of 1800.00 euro per one, today it is full 2000.00 euro per one - and if You want to obtain one imperforated sample (which was very rare and impossible to find) - be ready to go with 5 to 8000.00 euro in pocket.