The Floating Spellbook loot card is redeemable for a Gusting Grimoire loot item, which teaches the use of the Gusting Grimoire pet.
The Gusting Grimoire is very similar to the Lofty Libram, in both appearance and behavior, although the Gusting Grimoire uses a cool Fireball spell emote when summoned.
Floating Spellbook is a super common loot card – found in approximately 1 in 11 packs of Betrayal of the Guardian.
Betrayal of the Guardian booster boxes are selling for around $100 each, which would put the average price of this card at around $40, were you to try and pull it from a pack.
On ebay right now you can buy one for under $10!
Floating Spellbook loot cards on ebay:
Search current ebay auctions for Floating Spellbook loot availability and pricing.
Gusting Grimoire Preview Video