The Shinto Kanamara Matsuri (かなまら祭り "Festival of the Steel Phallus"?) is held each spring at the Kanayama shrine (金山神社)in Kawasaki, Japan. The exact dates vary: the main festivities fall on the first Sunday in April. The penis, as the central theme of the event--is reflected in illustrations, candy, carved vegetables, decorations, and a mikoshi parade.
The mikoshi parade bit is really amazing and makes more sense to me than "Sub White Mage for ALL THE THINGS!"
On Phoenix, stacks are selling for 50,000 each and there's a stack of pouches up for sale already. So availability is pretty good thus far, and I can only assume price will go down once the bullets aren't so shiny and new.