In discussions on the forums I keep hearing about how the OOG cost of coin physreps can be a significant barrier to plot teams in terms of what treasure they can put out. It seems to me like a simple way to mitigate this problem is to add additional denominations of currency. For instance, if there was a "5 gold" coin, then to hand out 7 gold would only require 3 coin physreps (5+1+1), not 7. That would also make it easier for PCs to make change when dividing up treasure hoards.