And considering that you can cast it from your graveyard, its hard to answer Hogaak
Adric, Mathematical Genius While Adric, Mathematical Genius is an excellent activated ability commander on its own, it acts as an ultimate support card for decks around this theme thanks to its doctors companion ability that can be used to add a new color to Commander strategies
Among them, Shipwreck Marsh is the most valuable at $4.99, and Rockfall Vale is in second place at $3.79
The "Magic player" demographic and the "software pirate" demographic has a lot of overlap, so this wont be a huge leap for most players
In this case, Urzas Sagas price is mainly driven by its demand
Kefka, Court Mage / Kefka, Ruler of Ruin Both Kefka, Court Mage and Kefka, Ruler of Ruin offer card draw, but Im most interested in the front half of the card