Madonna's fedora hat is also up for auction. Here's the description from Julien's Live Auction:
A grey felt fedora with black ribbon covered in inscriptions from Madonna's friends and paint splashes. Many inscriptions are written graffiti-style by Martin Burgoyne, Dondi, Fab 5 Freddie, Ronnie Cutrone, Daze, RP3 and Zephyr, among others. The paint is believed to be from Burgoyne, an artist who was roommates with Madonna during her early days in New York. The hat was given to a childhood friend of Madonna's, who lived next to her in a New York City loft in Soho in the 1980s.