Kate Middleton's Sexy See-Through Dress Sells for $125,000

It was the barely-there dress that helped make royal history.

On Thursday, a see-through knitted mesh slip worn by Kate Middleton at a 2002 fashion show sold at a London auction for a whopping $125,871; the Associated Press reports that the buyer was an anonymous British male. "He thinks it's an iconic piece," a rep for the mystery buyer said.

PHOTOS: How William and Kate have stepped out since their engagement

Indeed: In 2002, St. Andrew's University student Middleton, now 29, agreed to model the piece (designed by student Charlotte Todd) for a charity auction.

Made for about $48, the slip was actually intended as a skirt -- but fashion-forward Middleton wore the sheer number as a mini-dress, revealing her underwear and killer bod beneath.

PHOTOS: Kate's style evolution

Checking out Middleton in the front row during her sexy catwalk? Prince William, now 28, who reportedly paid about $317 for his seat at the show. It's widely believed that it was the first time that the heir to the British throne noticed his pretty classmate in a romantic light. They began dating soon thereafter.

PHOTOS: Flashback! Princess Diana's wedding day

"I'd like to call myself a royal matchmaker," dress designer Todd, 31, told The Associated Press. (She now works in an aquarium.) "It's definitely a showstopping dress!"

Middleton and Prince William tie the knot, of course, on April 29.

For more on the Royal Wedding, including rare photos, interviews with family and friends, details on Kate's new life as a princess and a tour of their lavish homes, order a copy of Us Weekly's Will & Kate: The Royal Wedding now.