Yeah, that was the problem, it is hard to have a fixed conversion rate because of just how much money some people in cRPG have, better to let the invisible hand of the free market determine the exchange rates.
In the past, strategus gold was just straight converted into crpg gold 1:1 when paying mercs, and that was the only way to get money out. Now with the market and strategus out people can trade for more than just heirlooms.