Every printing we track, with today's reference value. Cards someone is selling show the lowest price.
6 cards

Valkyrion the Magna Warrior
Stairway to the Destined Duel #SDD-001

Sinister Serpent
Stairway to the Destined Duel #SDD-002

Harpie's Feather Duster
Stairway to the Destined Duel #SDD-003

Seiyaryu
Stairway to the Destined Duel #SDD-E001

Acid Trap Hole
Stairway to the Destined Duel #SDD-E002

Salamandra
Stairway to the Destined Duel #SDD-E003