I live in a Dublin parish. Any monies received by the parish church for baptisms are divided as follows:
50% to the priest who baptised the baby
25% to the parish to cover costs (eg the cost of heating the church or for resources eg. leaflets etc..
25% to the diocese
So in the event of giving €50, the priest gets €25, €12.50 retained by the parish and €12.50 to the Dublin diocese.