Dave
There are reasons for the high differences in Mog prices. Not all Mil Spec Mogs are the same. The Swiss were pretty much the same platform and finish was done by the Swiss, and they took good care of them. The militaries ordered "per their needs", and if you look hard there are later 404s with a larger engine, power brakes, power steering, and air trailer brake setups( not necesarily on one truck). The diesel 406s and 416s don't all have disc brakes, earlier ones and some spec'ed ones have drum brakes. Belgium 416s also were fitted with breakers instead of fuses. You need to "dig" into each Mog you look at to see what the intended service it had. Most all the dealers know the different options and will point all anything unique, where a private owner may not know what things were on there for.
My opinion is to buy the best truck you can find ( and afford). I perfer one from a dealer first, mainly because they haven't " hacked" by an unknowing individual, or abused, and the dealers will usually go through them to make sure everything works.
Sean and Willy both are good people , and not mention above is Scott at :
http://www.expeditionimports.zoovy.com/
Remember one thing, buying a Mog in need of some repairs, may need more in parts than getting clean truck in the first place.But there are no garantee either way.
Dave Dunn