Foreman
Foreman200 GRAM in game (≈20,000 CROWN at the presale rate), 100 GRAM in the presale
A hired miner adds +220 base mining power on top of your drill and works next to it in the shaft. His power is multiplied by buildings, boosts and depth just like the drill. You can hire both miners, their power adds up.
Shards per hour from the miner = 220 × 300 × buildings × boosts × depth
At current competition that is about 1426.20 CROWN per day.
Crown Miner