But the design is so classic that it's super easy to find without resorting to dropping major cash for the Tom Ford original!
We found two equally affordable options that are super similar to Kate's dress.
Check 'em out ...AFTER THE JUMP!!!
Ha, like you could ever possibly forget!
The 24-year-old actress has donated her super seductive (and autographed!) gown to the Robin Hood Foundation, which will use the proceeds from the auction to benefit people still struggling from the aftermath of Hurricane Sandy.
Awww! It makes us feel warm and fuzzy all over!
Want to make the stunning dress yours?
Head on over to CharityBuzz and place a bid.
The auction ends on Thursday, so hurry up!
[Image via Apega/WENN.]