If you live in the right part of Australia, this might be for you (on Ebay.com.au)
http://www.ebay.com.au/itm/Yamaha-XZ-550-/320839047709?pt=AU_Motorcycles&hash=item4ab37f5a1d
That could be a good deal for someone willing to put some work into it. It looks fairly complete and has a lot to work with. :)