The prices change a lot, ranging from a couple of dollars to thousands depending on the card, the condition, the set, etc
Whenever Maui is used to challenge another character, the player can add an action card from their discard pile to their hand, which offsets the continuous problem of running out of cards
Ramp and card draw in one package
Not only that, this card has a good amount of willpower and lore-generating capability too, since each quest gets you three lore, so it can tank some damage and still help you win the game.
Tap her for a blue, her +2 counters is ready to go
Tifa Lockhart is one of a couple of good candidates for the Buster Sword, and you can have her on the board pretty early in the game too