dominaria mtg booster box United Dominary Jumpstart Boosters contain 20 Magic cards (including all the terrain you need to play) Dominaria United - Draft Booster

If you play Jace on turn four, there's a good chance you'll be able to hold up a counter spell or kill spell to protect him

Lightning Greaves is one of the oldest, yet most useful artifacts for a commander to wear and it's been reprinted many times since it's debut in Mirrodin

The cards ability to both counter a spell and grant a big mana payout the following turn is incredibly powerful

While this makes the cost increasingly worse as the game goes on, it still seems like a reasonable expectation and would be a bit too strong and consistent if it was always so cheap to get a better version of your commander out turn after turn