2 options come to mind:
www.techstore.com sells them for $75.75 plus shipping (but shows backordered right now).
the forums at arstechnica.com has a member called Antec CSR who, you guessed it, is a cust svc rep for Antec. You might message him/her and inquire.
Your really gonna hate this but I bought one from Onvia, got it last week and they sent me 2 cases but only charged me for one. Dont ask....I did the right thing and called em and they have issued a call tag to pick up the extra one.