Incorrect mana costs displaying on custom card art in store
The mana cost displaying on these cards in the deals section of the shop are all 1 colorless less than they should be.
Those are skins for the rebalanced (Alchemy) versions of the cards, which all have their mana costs reduced by 1. You can tell they are the rebalanced cards by the Arena logo to the left of the card title.
These cards were rebalanced in Alchemy with reduced mana values. Its why they have the Arena symbol next to the card name