Like most Magic: The Gathering cards, the value of Xanathar, Guild Kingpin 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 (Secret Lair Drop)
But the big Eldrazi arent the only ones that matter here
One of which is discard one and draw one
Will of the Mardu has some large token creation potential stapled to a removal spell as well
Creature - Angel Spirit Lurrus of the Dream-Den Companion Each permanent card in your starting deck has mana value 2 or less
My good friend PJ put it best recently: the more expensive (in mana) cards get, the fewer of them you can cast in a gameso you should always aim to resolve more six or higher cost creatures than four and five drops. This is the line of thinking that has led both of us away from more traditional concepts of Boros aggro decks, to a more competitive mid-range strategythe true aggro of EDH