Once this card was no longer available as a free incentive, it was not restocked often, as the Pikachu with Grey Felt Hat has been, allowing it to increase in value
The last ability triggers whenever you cast any Merfolk spell, not just when you cast a Merfolk spell from the top of your library
People use them for stage magic, training decks, and educational kits
Teysa Karlov neatly combines buffing your token creatures and doubling the benefits from aristocrat abilities
This card's Reverse Holo version more than triples the value of the common version, with near-mint (NM) copies of this card setting highs around 28 cents
Whether you spend five mana to kill a weak creature so you can draw more cards or target a stronger creature and draw nothing, you're always going to be left unsatisfied