1 Fees for processing an ecclesiastic annulment from the Catholic Church vary from $200-$1,000, but average about $500-$600. New York attorney Jeffrey B. Peltz quotes a legal fee of $1,200 for a simple annulment plus $343 for court fees ($1,543 total). 2  Fees for processing an ecclesiastic annulment from the Catholic Church vary from $200-$1,000, but average about $500-$600. 3  Appealing an unfavorable annulment decision can double those costs.