My daughter has these same dresses (Cinderella and Snow White). We purchased them on amazon for just under $30. They are very lightweight and comfortable. Because they're so lightweight, without all the puff, they take up practically no room in the suitcase (or backpack if DD gets tired of wearing it and wants to take it off during the day) and the fabric is nice for days when its super hot at the parks.
Also, the BBB has a newer package called the "Courtyard." It is priced between the crown and castle packages. It includes the hair, nails, make-up and they get to pick out a fancy tutu. Maybe that would be more comforatble paired with a cute t-shirt than one of their princess dresses. I believe the package is priced at $89.95.