Craft The World

When I saw this achievement,
I went back to my level 1, just for the pleasure of spending those coins and get the cheevo.

You get those coins as loot from some of the chunkiest monsters in the level 1.
Don't know yet for further on.
Then you go to the Goblin shop and spend them.
You still need the dwarves to pick up the items and bring them back to your stockpile(s).
(Tip: make a stockpile next to the shop when you can)