all fields with prices are problematic e. g. in countries of the european union with have introduced the Euro instead their former currencies.
Therefor some improvements should be made imho:
it should be possible
- to insert different currencies in the same field
- to set the exchange rates in the preferences
- to set the prefered currency to be displayed in statistics
- to set if e. g. "€" is shown in the statistics or "Euro" or "EUR" or no unit at all
- to set if a dot or a comma is displayed before the decimals
maybe I forgot some more details to make this perfectly working.