yeah, if the grounds of divorce is unreasonable behaviour then no need to go for separation. i think most fees even for a open close case is about 5k. to lower fees, make sure that you and your ex are in agreement on children, property, maintenance and other matrimonial property. that way, there will be no dilly-dally. try to get this down in writing in case the ex turns crazy and want to drag just for the heck of it.