I just came across this Q & A on the Knot and loved the answer so I thought I would share.
Q. What are the benefits of working with a wedding consultant?
A. A consultant will save you stress during the planning process and especially on the actual day of your wedding. They’ll also serve as your creative partner -- not just overseeing logistical matters -- but also providing a wealth of ideas, insights, opinions, and more. Don't have time to research vendors? *Consultants do all the planning and legwork. That way, you just show up to appointments, approve designs, sample menus, and so on. Also, consultants know the best vendors to hire, and they can score you great rates and negotiate watertight contracts -- after all, wedding consultants work with vendors all the time!
*Some planners offer different services, including full service and day of coordination, but any should be able to recommend good vendors for you.