Dear Matt and all,
The "2 Million on 200M" could be divided into three major groups;
Mi.Nr. 309AP (perf. 14:14 1/4, Plattendruck (=flat plate printing ?) )
Mi.Nr. 309AW (perf. 14:14 1/4,Walzendruck = rotary printing)
Mi.Nr. 309BP (rouletted 13, Plattendruck)
I uploaded the image from my album; sorry for the very poor quality, but it is from my childhood (with some recently added notes) when I spent a couple of years in Hamburg, West Germany in the 70's.
The German inflation stamps are rich of variation, and according to the Michel Deutschland-Spezial catalogue, this "2 Million on 200M" alone is further subdivided into 8 varieties. Mi.Nr. 309AP has three (a,b, c), 309AW has two (a,b) and 309B has two(a,b) color variations, and one watermark variation for 309APa. The most rare version is the Mi.Nr. 309BPb (rouletted, with "lebhaftorangerot" shade).
As Stampcrow mentioned, the used version is far much valuable (for example, 309BPb unused is 20-60EUR, used is 14000 EUR !!). Thus lot of forged cancellations !! Here is an interesting item from my collection, which evidently show how the forged used versions of the inflation stamps have been fabricated.
Happy collecting !