Ditto what costumeczar said. I became BFF with a wedding planner. She closed her biz when she had her baby and we have remained coffee-every-week friends. She and my other planner-friends do NOT expect lower pricing for their brides. What they DO expect is the best quality and SERVICE for their brides from the vendors the planner chooses to work with. Professional planners don't want to steer brides toward twits who might mess up the cake, the flowers or the photography for one of their brides.
THAT is the benefit of a planner ..... each side working with true professionals for a smooth transition for all parties involved!!