Old Datron DVM (year around 80's), how much it cost then?

Do anybody know of the approximate price of Datron 1041 (4-1/2 digits) and Datron 1051(5-1/2 digits) DVM back in the 80's?

The photos of these old DVMs selling on EBay are all shown with MOD/Royal Air force or government stickers on them so it seems to be a very proper choice among these organisations.

Thanks