For decks full of one or two drops, this card can be a nightmare for which they will happily trade multiple cards, as the Keg amounts to a two mana one-sided Wrath of God or sometimes even worse by killing artifacts like Cursed Scroll, Winter Orb or Ankh of Mishra
Spine of Ish Sah can be interesting if you cast it, sacrifice it to your commander, and fetch an 8-mana artifact to put into play the only one is Darksteel Monolith, by the way, but you get to cast the Spine again from your hand
But going through the Undercity is both a pseudo-ramp spell, a card-advantage engine, a pseudo removal spell, a tutor of sorts, a kill-condition and even a cheat-fatty-into-play spell all in itself
At $85.43, this 24-pack box equates to you paying only $3.56 per pack
But you need to sit down at the table with just 100 of them
While its too early to say anything for certain, this makes it seem like the current demand isnt sustainable