I'm currently doing an application design that involves sale of service. The application will ultimately be used internationally and will need to adjust prices based on user location.
Is it a good idea to store / work with all prices in an absolute unit? For example - credits. And I can specify conversion rules like 1 credit = 1 USD. What scenarios would I need to be careful about if I do this (and should I be doing this)?
One thing I can think of is problems during auditing if I change my conversion rules periodically. In which case I'll need to start storing conversion rules by date and the conversion process will also require the time of transaction to give the correct amount in any currency for that time.
Am I complicating this too much?