Here is a sample budget for help in setting conference fees.  However, it does not capture the conference common costs that are spread into workshops on a per-person-per-day basis.  These can be seen in the final financial statements for ACL-02 and ACL-03.

ACL-05 budget for setting fees

Here are the final financial statements that are currently available for recent conferences:

ACL-03 final financial statement

ACL-02 final financial statement