He's put the iconic piece of millinery up on eBay with proceeds benefiting his charity, From One Hand to Another, which helps underserved youth.
Meaning, yes, you could own the enormous Smokey the Bear/Arby's-esque hat that perhaps caused a bigger stir than anything Lady Gaga has ever worn. It's also a piece of fashion history, as Westwood designed it back in 1982 for her World's End store -- and while it's still listed on her website, it appears to be sold out. Though if it's simply the style you want, it may be worth waiting for it to come back in stock. The retail price is only $180, while it's currently going for $10,500 on eBay with nine days left on the auction.
Hopefully this doesn't mean Williams plans to retire the look. We know he has it in gray and red, too, so perhaps we can still count on this becoming his signature for years to come.