Check out this new article Wizards of the Coast posted recently:

Excerpts: Money Matters

We continue with Chapter 4: Money Matters. In the words of the sage Calathra 'Lady Coinmaster' Mralahard of Athkatla, "Flows of coins are like the pumping blood of dragons -- where they are hot and thick, life is vigorous, but where they are cold and few, life is feeble."