Or it may just be that not many packs of MTG Assassin's Creed have been opened yet, in which case we'd expect to see values come back down again pretty soon

Quandrix students, help me count to five: Primo, the Unbounded, which I will absolutely be building, introducing the first-ever base-power-0 matters commander that builds big Fractal tokens when creatures with 0 base power deal combat damage Yavimaya Bloomsage, the only creature in the prepare cycle to feature a flat-out banned card in Channel, made ready by putting a +1/+1 counter on a creature that subsequently has power 7 or greater Owlin Spiralmancer, a powerful creature that copies the first X-cost spell you cast every turn (including on your opponents' turns) Nexus Mentality, a member of the highly exclusive club of cards that can move counters between nonland permanents (sadly, this doesn't let you rip counters away from Dark Depths) Turbulent Wilderness, the final land (for now) in the Turbulent cycle When it comes to blue-green, it can sometimes be difficult to build a deck with a cohesive theme that doesn't lean too hard on broad themes like +1/+1 counters or Lands Matter

While a 1/1 hasty Goblin is pretty bare bones, its activated ability makes it unblockable unless the defending player has a creature with defender, which is highly unlikely and eminently useful in Goblin decks
Playing lands from graveyard is rarely useful, and if you unlock the Cellar, you probably dont' have mana to cast anything from your graveyard
That could be typical aristocrat synergies like Blood Artist and Midnight Reaper or cards like Serra Paragon and Lurrus of the Dream-Den that can recast the Cleric