A penny saved is a penny earned.
I lost a thousand yen (quite) needlessly [unnecessarily].
I (went and) threw away a thousand yen.
The balance is 1,000 yen to the good [bad].
The interest is at the rate of three sen a [per] day.
My pocket money is all gone.
Some people pin on paper money instead.
One hundred cents makes one dollar.
Contributions were collected on behalf of the bereaved family.