I just bought one - and for only $322 (including shipping). It's a Besson 600 Concert Tuba (upright) with some significant damage (creasing) to the bell, but that shouldn't affect the sound. I also wanted to take on 'rolling out the dents' as well, so it'll be fun learning how to repair as well as play tuba.

Should be here sometime either next week or shortly after the first of the new year. Of course, now I need to actually make room for it - our back room is starting to resemble the storage area of a middle-school band room.