You need a close straight on photo of the buckle before any can give you an answer sir.
a real nice late war Overhoff .
Must be steel , zinc coated and then silver paintet .
And nice condition
I'm searching for
special SA/NSKK/NSFK with maker marks
Link to my collection : http://www.warrelics.eu/forum/album.php?albumid=1175
Nice genuine late war SS EM buckle by Overhoff
Better to ask the question before you buy it. Nice buckle.
Have a look on various dealer sites, it will give you a rough estimate, if a private sale it should be cheaper than what a dealer would sell it for