second hand/dead DUO

Hi all, recently destroyed my cheapo ebay headtorch in france and thought it was about time to do things properly. I like the idea of using a duo housing and upgrading it, but as a student i can scarcely afford a couple of pints a week, so I was wondering if anyone would have a second hand DUO for sale, or a knackered one I could cannibalise?
Cheers to anyone who has any offers