Hi! I'm new here too! ^_^
I'm gonna do the same gown too for the Dec 18+ Premiere and so far I came up with this idea while still keeping the cost down (it was an unplanned costume! :-P )
The original costume, as mentioned at AlleyCatScratch, is made of Velvet (Crimson Red/Scarlet & Black/Dark Bulgary), Laces and maybe some embroyies. It kinda follow the design of a Jumper for the body part and the usual Long Sleeves.
What I'm doing instead is to make the Gown out of Black Velvet for the "Jumper" part, Crimson/Scarlet Silky Satin for the "Blouse" and Sleeves, Rose Red Acetate Lining for the Sleeves Lining and Dull Gold/Brownish Lace for on top of the Blouse and on top of the upper sleeves. So far, I had calculated that it'll cost way less than SGD100 (USD54 for the fabrics) since I'm buying from the usual Arab/Indian/Chinese Cloths Shop here instead of Spotlight, the equivalent of Joann's.
I'll also appreciate some tips on it, especially the pattern for the sleeves.