Don't forget to factor in shipping costs too
If a creature with persist that has +1/+1 counters on it receives enough -1/-1 counters to cause it to be destroyed by lethal damage or put into its owner's graveyard for having 0 or less toughness, persist won't trigger and the card won't return to the battlefield
Zirilan, in particular, seems like an old card that might spike in price if its ever discovered on a larger scale
This deck all about X costs in cards, and Hydras happen to be the best Magic creatures in these colors for X
Sadly, many of the early Japanese cards are without identification codes (instead, their Pokedex number) and so are much harder to track
Ravensburger has shed light on what to expect from its ninth Disney Lorcana set, Fabled