How will people get paid in a monarchy country?

Currency tends to be scarce in a Monarchy. The leader, overtime, takes over the monetary currency whether it be gold or silver (History shows, that the system of paper currency will fail unless it is supported by another strong country or system.)

Bartering will tend to take over as a method of trade and commerce among the common citizen.

("I'll give you a loaf of bread if you rake my lawn.")