Yeah, its the Halo 3 edition headset. They usually go for $20 - $30 new, with the charging cord included. As-is ones usually go for around $5 - $10. It would be well worth your while to try to get a mini-USB cord for it (perhaps one from a digital camera would work) and see if it powers on and holds a charge.
If it were known to work, that would at least triple its value. Good luck! Fanned you too! :-))