Bicentennial medallion Birth of the U.S. Marine Corps

This is a commemorative medallion honoring the Birth of the United States Marine Corps, struck in an unknown (to me) metal, which may be bronze. It is three inches in diameter and weighs 9.5 ounces on my old postal scale.On the obverse side (first picture) is a depiction of a colonial marine, and the "Eagle, Globe and Anchor," the emblem of the Marines. In the background is a charging Marine and a couple of cannon. Arched across the top of the medallion are the words, "BIRTH OF THE U.S. MARINE CORPS" and arched around the bottom "10 NOVEMBER 1775" On the reverse of the Medallion is depicted a squad of Marines in battle and the words, "UNITED STATES MARINE CORPS BICENTENNIAL 1975". The third picture is of all four coins in the set. This auction is just for the Marine Corps medallion. The others are listed separately. I have no idea of the value of this medallion. I figure it'll cost the better part of ten dollars to list and ship it so I'm starting the bidding at $10.00 with free freight and no reserve. If someone buys all four, I may make a profit on eBay. Imagine that!!! :)