Church of England fees are set nationally and apply for St Martin’s, and for all other Church of England churches. The fees are set and published by the Archbishops’ Council Church House, Great Smith Street London SW1P 3AZ
A short summary of Church of England fees can be found here and contains information about funeral and wedding fees. (There is no charge for a baptism service).
A more detailed list of Church of England fees can be found here and contains details of how fees are broken down and includes the fees that apply for memorials in the church yard.