panther, did you play Transport Tycoon?
Of course it has all multiplies being straight integers. For example, 1 euro=1usd, 2 usd=1pound, 1 usd=100 yen. I'm not suggesting downloading new currency data every day straight from your government bank
In TT, it worked with zero problems - all currencies were a multiple of a british pound, so you never had 2352352351 values, it was always clean and simple. Of course this doesnt incorporate currency changes but then again we're playing a game set in 1999, we can stick with currencty rates from there, simplify them, and go with them.
Of course, benifit is purely cosmetic, but why not?