Collecting the "Inflation" period of Germany is both interesting and challenging. There are "about" 259 basic stamps to collect (not counting color shades), 26 different rate periods (from October 1, 1918 to December 1, 1923) to keep one busy and a very good supply of "mint sheets" that can be fly specked to death. Let's discuss each aspect and provide a little extra information to help you on your journey. If you have additional questions, feel free to e mail me for an answer.
Before we even start discussing the actual stamps, there is one subject that we have to get out of the way. EXPERTIZING. Other then a common, mint example, everything in the inflation era has to be "expertized". Don't spend one extra cent on any premium for a color shade or "used" example if it is not expertized! I don't care who the seller is, what his assurances are, how good the deal looks, just don't do it, plain and simple.
So what is this magical "expertizing"? (My feeling is that it resembles the old fashion medieval "guild", but that is only my personal opinion. An "expert" has to buy his way in, purchasing a retiring experts reference collection, spend an apprenticeship and pass a test. But they do know the material and carry a lot of weight when it comes to determining the actual value of an item). One sends the material off to the "expert" (in Germany, of course) who inspects it and if it is genuine, applies his expertizing mark or issues a certificate for the item. And this becomes the object's pedigree, testifying to the fact that it is exactly what it appears to be. That sounds great, but there is a cost. Up to 4% of the catalog value, depending on condition, with a 3 Mark (about $1.50) minimum for each stamp inspected. Which brings up a horrible inconsistency. All catalogs state that some items should be expertized, and then go on to give those items price listings that are less then the expertizing fee. (And don't forget to add the postage). A list of the experts can be found at the back of the Michel catalog.
Now that you are familar with that subject, let's move on to the real information.