I know that to some extent this has been exercised before, but I would appreciate opinions on my situation. I have a D700 with several prime and zoom lenses. None, however, for various reasons really suit portrait use. I have the 60mm lens and wondered about buying a dx body, perhaps a D200 - they are now very inexpensive - and it would double as a spare body, rather than buying a very expensive portrait lens for the D700. Is there any sense in this approach?