Terapagos EX, Briar, Galvantula EX, and Lacey are some of the most expensive and sought after cards in the set
Who can say what a fickle market will be attracted to next
Additionally, theres not enough graveyard support for the deck, even with terrain, unless you were using something like Burning Abyss or Lightsworn, which could brick with these in hand.
This effect can persist across turns if all five normal monster slots are occupied, canceling its summon Related: Best R rarity staple cards in Yu-Gi-Oh
List the missing cards, then head to Cardmarket or TCGPlayer to buy commons and uncommons for a few cents each
Obviously being a creature is a definite drawback but it's cheap to reflect that, and while what you can use it for is limited, it's limited to exactly what you want it for anyway