Stamp collectors can always be a bit sanguine when the rest of the world gets upset if the Producer Price Index goes up a bit. German inflation during the early Weimar period defies belief until you actually see it. The scan here is of the front and back of a 1923 cover with over 30 billion marks of postage on it. Inflation was do high that postal patrons had to add stamps to envelopes as they were waiting in line for service, as rates changed that fast. Collectors enjoy covers like this as a sort of hathos- a newish web word that means an attraction to seeing something that is really horrible. Imagine the suffering inflation like this caused.