Bronze Drill

Bronze Drill2 GRAM in game (≈200 CROWN at the presale rate), 1 GRAM in the presale

Adds +1 mining power. The power of every drill you own adds up, so a new drill does not replace the old one, it stacks on top.

Shards per hour from this drill = 1 × 300 × buildings × boosts × depth

At current competition that is about 6.48 CROWN per day, paying back in roughly 30.90 days.