Some of the FF books from Tin Man Games are on sale; the Zombies, Lizard King and House of Hell. Prices vary but they're all at a discount.
Fighting Fantasy: House of Hell $5.99 > $1.99 iTunes Link Fighting Fantasy: Blood of the Zombies $5.99 > $1.99 iTunes Link Fighting Fantasy: Island of the Lizard King $5.99 > $2.99 iTunes Link