Medal - New York City Bicentennial (Perhaps Gold)

I was left this medal from my deceased Father in-law and was wondering what the value was for insurance purposes. Looking on this site, it says that it was stuck in bronze although the one I have came with a Cert of Authenticity, saying that its a “limited edition” of 1000, stuck in 18k gold. It weighs approximately 22.4g, and the color is brilliant. I wasn't able to find much information online. Any help would be appreciated.

Melt value would be acceptable for insurance. 22.4 g @ 18k would be 16.8 g (.540 troy ounces) pure gold @ US $2508 / troy ounce (today) is $1354.

Here is some information on American Numismatic Society.