Call around to different sites. You wouldn't believe how widely fees vary from facility to facility. Consider a membership.
Many churches charge less for weddings of members than nonmembers.
If you are planning to settle down in the town where your wedding is, consider joining the church where you'd like to be married. Ask about any discounts. For example, some churches and synagogues offer discounts on wedding invitations as a fund-raiser. Have a friend do the music. Not only will your musical friends save you money, but using them may make your service more personal.