I would much rather have the consistency of the other cards giving a static discount, as you aren't guaranteed to be playing against anyone with counters to remove
English market: Global demand , grading culture, and official play create durable resale pathways
Volrath's Stronghold Market Price: $101.44 As we've seen time and time again, one-off nonbasic lands from older Magic sets tend to be worth quite a bit, even ones that are relatively pedestrian by today's standards (looking at you, Undiscovered Paradise, one of the most valuable Visions cards)
Being able to cycle it can be invaluable when you're ahead and being able to exile at instant speed can be invaluable when you're faced with threats that are indestructible or recursive
Older cards with effects that are basically menace (think of Gorilla War Cry, Searing Spear Askari, Demoralize, and Wind Spirit) have been errataed to add the keyword in replacement of the rules text