I think lowering the ticket prices should be allowed whenever you want (that would more or less be the same as giving away tickets for free).
Raising the prices... not so much...
Größter Knecht aller Zeiten aka His Excellency aka President for Life aka Field Marshal Al Hadji aka Lord of All the Beasts of the Earth and Fishes of the Seas aka aka Conqueror of the Buzzerbeater Empire in Europe in General and Austria in Particular