I found a pair of XM3s in a trash can last year. Someone was doing a big house clean and threw them out. They were dirty and looked like a train wreck. I took them home and tore them down completely for a thorough cleaning and made them look new again. I also bought new ear pads for them on eBay and a case. Apart from one very small gouge on the head band, they look perfect now. Battery is great too.

They seem to be headphones that can take some serious punishment, so they're probably fine.