It appears that Mi 45B in many offers may actually be Mi 45A. The problem is that in my opinion the Liechtenstein 2 Rapen, yellow stamp, in not the very rare Michel 45B with 12½ perforations but a much less expensive 45A with 9½ perforations. This is a very subtle difference but 45B has a Michel catalog value of €500.00 and 45A a catalog value of €6.50!
Both look very much identical, however I counted the perforations on the 2 Rapen stamp displayed which indicated to me that it was definitely a 45A and not a 45B. I also noted this hard to detect substitution elsewhere for this stamp listed for sale on other ebay country sites. Normally, the 1921 A series is more expensive than the 1921 B series with this one notable exception.
If you doubt my analysis, you might like to have a professional philatelist confirm my opinion.
Cort MacLean Johns