Whats the biggest factor affecting value
It comes back tapped and its presence on board is tame, but all the knobs are turned in the right direction
That's the difference between knowing you have 9 ramp sources (one short of the baseline) and knowing that three of those sources are conditional on your commander being in play, making your reliable ramp count closer to 6
While they take a little more work than a traditional tutor like Demonic Tutor that put the card directly into your hand, its easy enough to build around them that entomb effects often become critical pieces of reanimator and other combo-adjacent decks
Like most Magic: The Gathering cards, the value of Enduring Curiosity depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Duskmourn: House of Horror)
Koth, the sets alternated between showing two rival factions, and two rival planeswalkers, and often tie into current or future storylines, which is of course why this has our attention