Britney Spears' old costumes are about to net one of her superfans $1 million ... or at least that's the hope of the collector who's unloading 7 vintage Brit looks.

The crown jewel of Dana Proctor's collection is the iconic outfit Brit wore during her 2001 "I'm A Slave 4 U" performance at the MTV VMAs. Python not included, but she's also hawking 6 other wardrobe selections from Brit's music vids, award shows, and Super Bowl performance with Aerosmith.

Some highlights:
- "Overprotected" music video Levi’s chaps
- 2008 VMAs custom Versace Atelier dress
- "I'm A Slave 4 U" music video costume
- "Me Against the Music" music video (feat. Madonna) costume

Important sales point: Dana's ONLY selling the wardrobe as a set. Her eBay auction ends next week, and so far the high bid is $33,400 ... so, she's a long way off that $1 mil goal.

But you know Brit fans represent.