A lot of decks will kill you before six mana
Yugioh is confusing indeed, so take the higher prices as a reference, and in some cases card was never sold, so its just a guess
But luckily for us, Otharri has a potent activated ability that lets you recast it from the graveyard for cheap, so the Bird
BT13-101 U Tamer Miki Kurosaki & Megumi Shirakawa Color Black Yellow Cost 4 Card Text 1 [Effect] [On Play] You may play 1 Digimon card with [PawnChessmon] in its name from your hand without paying the cost
Careful Consideration You dont quite get enough for 4 mana here, but when you need someone to draw four cards, Careful Consideration does that
change this card to Defense Position, and if you do, negate that targeted card's effects, until the end of this turn