The "Blue Back No Number" versions (without number) are considered from the very first print run and are the rarest, per PSA CardFacts historical data
As a rule of thumb, Ive found that if the card(s) in question cannot win you the game outright, the answer is usually No. Cards like Insurrection, Finale of Devastation, Rise of the Dark Realms, Armageddon, and Expropriate are cards that often belong to this category, and should be added very sparingly to your deck
Each player has their own deck of cards, either one previously constructed or made from a limited pool of cards for the event
Plus, if you're a TCGPlayer subscriber, you'll get 13% or more back (12% base plus 1-3% monthly loyalty bonus)
In addition, you gain rightful ownership of a small keep somewhere in the world