I've got mixed feelings about baptismal fees payed to the church. I understand that it costs money to heat the church, to fill the font with water, to run the lights, etc...and this can be quite expensive for larger churches. But again, I'm not sure that I'm completely at peace with it.
However, I do encourage people to give an honorarium to the priest, chanter, sacristan, etc...anyone who may be helping with the baptism. There should be no set fee, people should give what they want, but we need to understand that the priest takes time away from his family, often on evenings and weekends, to celebrate the sacraments for his parishioners. Yes, that is his job as a priest, but we the faithful should recognize the sacrifice he is making on our behalf, and make a small sacrifice of our own to help him. We pay hundreds of dollars for crosses, baptismal gowns, etc..., but we find it apalling to give $50 dollars or so to the priest who hasn't seen his family in virtually 4 or 5 days, but still comes to the baptism and joyfully celebrates it. The priest should never, ever charge for the sacraments, but we should be willing to give joyfully for the welfare of our pastor and father in Christ.