Buy Cocktail Dress

I want a dress similar to this style (short, cocktail dress) for my cousin’s wedding:

http://www.splendicity.com/files/643/2008/12/20081228-phoebe-couture-lace-tiered-dress.jpg

Where do I go?? I’ve tried Neiman Marcus, Nordstrom, Cache, Macys… I never thought it would be this hard to find a dress.

http://www.betseyjohnson.com/Women_Dresses_View_All/pl/c/1101.html