I never vote for realism to get in the way of fun.
I find it hard to see how a complicated money system would make it more fun. It would be hard to keep track of all of that and you would probably need to spend a lot more time at the bank, especially at higher levels, if currency has weight.
HOWEVER, a complicated money system could be used to increase how much people need to farm, and when used in moderation, could increase their play time. This is why I think there is merit to special, rare, currencies attributed to special, rare factions.