Hi Karl,
If you haven't already, talk to these guys:
Classic Unimogs / Classic 4x4 - Unimog 404/406/416, Volvo C303/C304
They deal in Pinz's, Volvos and Unimogs, so they can easily answer all your questions about relative price and availability. Compared to my Volvo Sugga, Volvo C303 or C306...