From Twilight Lexicon:
Alfred Angelo is the manufacturer the Bella’s Wedding dress that was designed by Carolina Herrera for the movie Breaking dawn Part 1. According to the Alfred Angelo site the dress is currently priced under $999, and they give the details below. Best part of the details in our opinion is the gown isn’t just limited to smaller sizes!
BELLA’S BRIDAL GOWN
As seen in Twilight – Breaking Dawn Part 1
Bella’s beautiful bridal gown
Long sleeves with button detail
Cut out back with lace embellishments
Sizes: 0 to 30W