It makes sense for a stamp vending machine to have some limits and not print any amount of stamps or stamps of any value. The vending machines from the Deutsche Post are a little weird though:
You can only buy stamps worth 100 EUR at a time. Makes sense.
The maximum face value for a stamp is 36.75 EUR. Hmmm…
You can buy up to 100 stamps at a time, and the minimum face value is 1 cent. The poor machine will print worthless stamps for five minutes. The obvious question now is: What is the minimum amount of money that I have to invest to make it run out of paper.