Platinum Hammer

This and the gold version are the same rung, so build whichever ore your world generated and stop thinking about it. What the upgrade buys is speed on background walls and on the constant reshaping that any real build turns into.

The reforge math is worth knowing before you hand the Goblin Tinkerer your money. Mining speed rounds to the same result across most of the top modifiers on a tool this slow, so a Light or a Quick roll leaves you exactly where a Legendary would. Take the first one and walk away.