Well I'm going from a Mil4 to a Mil6 in my Kahles and that is $268.00 so might have similar pricing structure. Unless your going to some flavor of Horus, I think there are licensing fees associated with that?
You can do a search in the archives but If I remember correctly it is in the $500-$600 range. Jerry from Schmidt & Bender posts on this site sometimes you may be able to P.M. him and get an exact quote.