2, 50 Fr on 2 Mark German Empire, 25 : 17 perforation holes, rare color blackish ultramarine, plate flaw I "break in crown left", cancelled "Postpruefungsstelle 33 (* b *) 25. February 1918", flawless condition, photo certificate Heinrich Wasels BPP "The condition of the stamp is impeccable.", Michel 1. 500.- without surcharge for the plate flaw, which is worth three times the cheapest type, which would result in a calculated value of 4,500 euros.