Research by The Scottish Wedding Directory™ (who know a thing or two about the wedding business!) suggests that the three most important "success-critical" items to consider when structuring the budget for your wedding are:

              — your venue
              — your evening music
              — your bridal gown

There are clear implications about the relative impact of these on your big day ... and notice that music features well before such things as photography, flowers, video, cars, favours, etc..