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!!!
They swapped styles!
The supermodel opted for a skin tight, red one-shoulder dress by Preen, which she paired with some fierce Saint Laurent studded heels.
We're not crazy about Heidi's bouncy curls, but we won't hold it against her.
Which judge's look do U prefer? Heidi or Mel B???
[Image via Daniel Tanner/WENN.]