Banking and the coining of money are both handled entirely by the dwarves (up until Rosie Printer creates the technology for the ). There is one currency throughout the supercontinent, making international trade straightforward. The idea of a local ruler minting his own coins would be regarded as wrong-headed.
The dwarves, whatever their other faults, are both scrupulous and exact about alloys, weight, counting and contracts, and whatever distrust they attract does not include these aspects of life.
There are three major denominations of coins: copper anvils, silver hammers, and gold pillars. Sixteen anvils make a hammer, and sixteen hammers make a pillar. Coins are minted in quarter-anvil, one-anvil, four-anvil, one-hammer, four-hammer, one-pillar and four-pillar denominations. The obverse shows the object after which they are named and a number (1 or 4, as applicable), while the reverse shows the mark of the mint where they were coined.
In Gulfport, a prosperous trading city, a quarter-anvil will buy a snack from a street vendor, an anvil will buy a basic meal. Among the labouring classes, to say someone "thinks he's a hammer-man" implies "airs above his station", that he thinks his work is worth a hammer a day, when the usual daily pay for an unskilled worker is about half that. Prices vary from this in other places, of course, in conformity to the famous law of supply and demand, but wherever you go, a gold pillar is a lot of money by the standards of an ordinary person.
Rough NZ (early 21st century) money equivalents:
Smallest coin is 1/16 of a copper anvil (50c).
Other copper coins: quarter anvil ($2), anvil ($8), four anvils ($24).
16 anvils make a silver hammer ($96).
Other silver coin: four hammers ($384).
16 hammers make a gold pillar ($1536).
Other gold coin: 4 pillars ($6144).