"Anyone can fight alongside these preternatural beings but to become one players must purchase the all-new outfits as a special bundle on the website or as separate items in the in-game store," explains Electronic Arts.
Bundles containing all the parts to complete one's transformation into a Royal Werewolf or National Vampire during the "special month long event" can be bought for 1800 Battlefunds ($12.86) each--a savings of $8.64 over buying each part on individually, with each bundle packing an exclusive attack and emote abilitiy.
As for those unwilling to pony up the cash, it seems you're out of luck. Though the game is still free-to-play, the Valor Points one earns in-game can't be used for these items. BOOM video 3915