50 000 000 Mark

Altenburg's Spielkartenfabrik — better known internationally as the playing card manufacturer that produced Skat decks — pivoted to emergency currency printing during the hyperinflation peak of 1923, as scores of German municipalities scrambled to commission notes locally rather than wait on an overwhelmed Reichsdruckerei. The firm had the presses, the paper stock, and the ink; the denomination reflects where Germany was by late 1923, when fifty million marks was roughly the cost of a streetcar ticket.

Notgeld of this magnitude is common as a category but genuinely specific as an artifact — each issuing city tells you something about local industrial capacity in a crisis.