IIRC, the "german-made" guns were manufactured for Weatherby by JP Sauer,
from c. 1959 - 1973. Some consider them to be "the best of the bunch" and
pay a premium ( 15-30 % ) for them over the others. Watched German-born gunsmith Siegfried Trillus work on quite a number of them when he was with Sauer Canada.
Kahles are indeed a fine scope - as are Zeiss and others. Don't recall a
Weatherby/Zeiss connection, but someone may know.
A "Sauer" Mark V Weatherby in 300 or 340 with an appropriate sized Kahles in good condition ... would think $ 1000 not to be out of line, perhaps a little more if in really good shape with a low round count.