If you are recently engaged and venue searching, hire your planner first.  A planner can give you all the ins and outs of venues, plus let you know where additional costs are. For instance, some venues require a tent if it rains and some venues require additional security if your guest count is over a certain number. These are thing you may not have thought about or considered, and a planner can inform you prior to contracting a venue. In the end, a planner can help you best manage your budget.