While the card pool that is legal in Magic: The Gathering's Pioneer format is certainly more limited than it is in Modern, there are still some very pricey cards in this newly announced constructed format. As examples, older cards like Ugin, the Spirit Dragon, Jace, Vryn's Prodigy, and Liliana, the Last Hope each cost in the range of $40 to $50, but they all fall short of being the most expensive card in Pioneer. Indeed, that honor is reserved for a brand new, extremely powerful Magic: The Gathering Planeswalker.
At the time of writing, Oko, Thief of Crowns, which was released as part of the new Magic: The Gathering Throne of Eldraine set, is the most expensive card in Pioneer. More specifically, Oko currently has a median price of $60 on TCGplayer, and while it is certainly possible to find cheaper copies of the Thief of Crowns, TCGplayer medians are what are being compared for the purpose of this article.
However, the announcement of Magic: The Gathering's new constructed format is not the reason for Oko's current price, as it comes following a banned and restricted announcement that was made at the beginning of this week. In this announcement, Wizards of the Coast officially banned Field of the Dead in MTG's Standard format, and Oko, Thief of Crowns saw a significant price spike immediately thereafter.
Indeed, it seems that players believe that Oko is primed to fill the hole that has been left in Standard with the banning of Field of the Dead, and that is certainly a reasonable expectation considering just how powerful this new Planeswalker is. That said, the price of MTG's Oko, Thief of Crowns has already begun to decrease following its initial spike, and thus fans that are interested in playing the cards in their Pioneer decks may want to wait to see where things settle in the coming weeks.
To note, Pioneer card prices are sure to shift as players learn more about the format, and the costs associated with some cards may even push past Oko in due time. Until then, though, the Thief of Crowns can enjoy its moment in the sun as the most expensive card in Magic: The Gathering's Pioneer format.
The Magic: The Gathering Throne of Eldraine expansion set is available now.
Source: Scryfall