The ability to recast the adventure side once it dies as a creature from the graveyard is very good, and also keeps the creature coming back for various triggers, like leaving the graveyard, anything that cares about instants and sorceries being cast like Professor Onyx or Sedgemoor Witch, or when you cast creatures or they come into play
Even if you open Ancient Tomb #46 (the second cheapest), you still opened one of the most valuable cards in the bonus sheet (and set in general)
This absolute planet of a Pikachu from Vivid Voltage was a difficult and rare card to pull, and its value does a good job of reflecting that
Apollousa being in Rarity Collection 2 allows newer players to get their own copy without having to drain their bank accounts
Thats why every time this Synchro Monster is banished, it pops right back to the field next turn
The Azurite Sea Illumineers Trove is exactly that