Go to the indicated location in the Krypt to purchase the corresponding stage for the indicated amount of koins.

'Dead Woods' Stage in the Krypt's Cemetery Grounds Area
Go to the Large Grave at coordinates -18, 9, and purchase it for 1,120 koins.

'Kuantan Palace' Stage in the Krypt's Shao Khan's Tomb Area
Go to the chest at coordinates 4, 8, and purchase it for 1,240 koins.

'Outworld Marketplace' Stage in the Krypt's Shadow Spider's Hive Area
Go to the Glowing Ball at coordinates 7, 42, and purchase it for 1,150 koins.