The Pitcairns are tiny islands in the South Pacific, 2000+ miles off the coast of Peru, where mutineers from the famous British ship HMS Bounty lived for 20 years before being discovered by American whalers in 1808. Now a British colony, the Pitcairn Islands have issued a few moderns commemorative coins ... but they did not issue this one!
This coin is some kind of semi-official British coin which I have not been able to fully track down. Apparently it is a Fleur Du Coin (FDC) or modern piece issued for collectors and investors. It is not listed in standard catalogs, and, as such, its authenticity and gold content are subject to question.
Sellers on eBay and a few coin web sites state that this coin contains 7.8 grams of 14 karat gold. If this is true, and with 31.1 grams per troy ounce and 24 karat being pure gold, then the gold content is:
7.8 x (14/24) / 31.1 = 0.146 troy ounces
At the current price of gold at $1325 US dollars per troy ounce, the value of this coin is 0.146 x 1325 = $193. Special packaging, a proof finish, and certificates of authenticity mean nothing to value. The coin supposedly contains $193 worth of gold, but I would not buy it. There are plenty of other gold coins that have reliable guarantees of authenticity and purity.