What is the Average Cost of an Officiant? 

(From article on wedding officiant directory)

It’s difficult to get a true average price of wedding officiants because there is no reliable data on the subject. While amateur officiants and individuals simply looking to make a few dollars may charge a couple as little as $100-$250, the average fees for professional officiants typically range from $400 to $800 depending on experience and the level of service and customization they provide. Many clergy such as priests and rabbis can cost well over $1000, often asking couples to make a donation to their church or synagogue in lieu of being paid directly. Factoring out the low rates from amateur officiants as well as the impact of individuals performing ceremonies at no charge to the couple, our determination is that the average cost for a professional wedding officiant is roughly $600 per ceremony. 

...plan to spend $800 total on any ceremony fees and officiant donations... - Brides.com