Depends on what you consider reasonable I guess
The biggest source of Unimog links I know of is at
www.rockymountainmoggers.com There you will find quite a few Mog sellers. I bought mine from Sean Phillyaw near Atlanta, great guy. He owns
www.eurotruck-importers.com You can also find them on the email list at topica.com, the list is called mogml.
The early gas powered 404 series trucks normally sellfor $6-8,000. Getting into the more substantial diesel powered models (406,416) means spending anywhere from $10-40,000 depending on condition and equipment.
Brent