If your DD still wears the girls sizes the Burlington has an amazing selection of dresses and almost always under $30.
My issue with my tween is that she is wearing a Juniors medium or a 9/11 - she is 5'4" tall and already 125#'s - she can no longer wear a girls 16, no more princess dresses for her.
Finding her Christmas dress was tricky, she is only 11 and does not have all the necessary accessories needed for a proper fit of many of the Junior styles nor are many of them Mother/Father approved. We finally found a nice babydoll style that was not too short or hoochie at JC Pennys.