An internet casino confirmed it had purchased the sandwich, saying it had become a “part of pop culture”.
Goldenpalace.com says it will take the sandwich on world tour before selling it and donating the money to charity.
Diane Duyser, from Florida, says the sandwich has never gone mouldy since she made it 10 years ago.
By the time the sandwich auction closed on Monday the sale had received over 1.7 million hits on the auction site.
“We will definitely use the sandwich to raise money for charity, and we hope it will raise people’s spirits as well,” said Richard Rowe, the casino’s CEO.
“With the… thousands of search engine queries, it is obvious that this is something people want to know more about… and Golden Palace will help spread the word.
“We believe that everyone should be able to see it and learn of its mystical power for themselves.”
Last week, Mrs Duyser told reporters the sandwich had brought her luck – including winnings of $70,000 at a casino near her Florida home.
Mrs Duyser says she noticed the image burned into her sandwich as she was about to tuck into it in autumn 1994.
“I went to take a bite out of it, and then I saw this lady looking back at me,” she said, according to the Chicago Tribune newspaper.
“I hollered for him,” she said, gesturing to her husband, Greg. “It scared me at first.”
She says she has done nothing to preserve the sandwich except keeping it in a plastic box, but “it doesn’t fall apart or crumble or anything”.
Nevertheless, before auctioning her sandwich Mrs Duyser cautioned buyers that it was “not intended for consumption”.
The item has inspired sellers to place dozens of spin-off items on the online auction site, including attempts at replica burnt toast, T-shirts, ornamental plates, and domain names.
One seller is even offering a “Virgin Mary” sandwich toaster – though the item description includes the caveat that the item “may or may not reproduce the Virgin Mary image”.