The flexibility of being able to choose a value for X is great because we might have an early-game case of wanting (or needing) to cast it for X of one or two, or we can wait until late-game and sweep a much bigger battlefield
$20.99 Iona, Shield of Emeria From the Vault: Angels $1.79 Flash Masters 25 $12.99 Golos, Tireless Pilgrim (Promo Pack) Promo Pack $89.99 Recurring Nightmare Exodus $1.49 Sylvan Primordial Gatecrash $1.29 Upheaval From the Vault: Annihilation $9.99 Dockside Extortionist Commander 2019 $1.49 Prophet of Kruphix Theros $7.49 Primeval Titan Iconic Masters $2.49 Balance Eternal Masters $2.49 Golos, Tireless Pilgrim Core Set 2020 $17.99 Yawgmoth's Bargain Urza's Destiny 0 results found
In Commander games, Dack Faydens second ability snatches any of those surplus Sol Rings or Esper Sentinels that your foes don't need that badly
It all depends on the artist and what they feel is a reasonable price for their wares
You can get more card draw from Harvester of Souls as opponents sacrifice more of their creatures
Being indestructible helps a lot , and casting spells for free
