Any extras (essentially, rental and decoration of the site, services of choir, etc.) are extras. My own parents were married by the priest in the rectory (of course this is years ago) at no cost.
Even the priest's stipend can be waived. But it's as reasonable to pay the officiant for his time as it is to pay a caterer or a florist.
You know, it's all semantics. The fact is Catholic churches in Philadelphia have been charging for the sacrament of matrimony for at least two decades. Is the charge for the use of the church or the priest's time or a combination of both those things? Is it an actual fee or is it a donation? In the words of Hillary Clinton: What difference does it make? If you can't be sacramentally married without forking over some money to your parish, then there's a fee for the sacrament.
Can the cost be waived? Absolutely! But the truth is most young people in Philadelphia who are hardpressed to come up wtih $500 unfortunately aren't considering a sacramental marriage in the first place. As I said in a previous post, having a Catholic wedding a) locally and b) announced six months in advance raises the price of the reception. We have to hope and pray the couples who avoid sacramental weddings because of the associated costs will ultimately return to the Church and have their marriages blessed. I've seen it happen several times so there is hope.
Come to think of it, there’s a charge for First Communions too. My daughter was in the hospital so I brought one of my grandchildren to the first Communion practice (at a parish other than my own) and when we signed in I was told we hadn’t yet paid the fee. A lot of folks hadn’t paid yet and they made a point of saying if it was a hardship to see the DRE. I’m sure it was a hardship for some folks - the fee was a $100!