A 12/12 creature with trample wouldn't be great at 12 mana, but the whole point of Ghalta is that your other creatures reduce her cost
Second, sometimes rule breaking cards demonstrate areas for future design
A witch once foretold that Glavin would die surrounded by unimaginable wealth
5 Dragon Master Lords A Celebratory Card Quarter Century Secret Rare Market Price: $105.73 There are plenty of cards that appear throughout the 25th anniversary celebration of Yu-Gi-Oh
While this may be relevant if you, I dont know, intend to use them to make a cube, or for every single deck you have, it's more than the average player would use
For this search I am going to be more specific because there is no organization to the cards as we find on TCG Player or Troll and Toad where all the buying options for a specific card are grouped together