How much would a bronze medal from pope paul VI be?

okay so my grandfather gave me a a bronze medal, 1�" in diameter, with papal seal on obverse and embossed "Paulus VI Pont. Max. U.N. 4 Oct. 1965" tracing the rim. On reverse is a sculpted image of burning bush and the Latin phrase, "Amoris Alumna Pax." Contained in felt cover. he got it when pope paul VI visted the UN on oct 4 1965, and im curious and woder how much it could be worth