Your melt value is off by approx $90 as it's a .900 purity coin and you've calculated the value at .999 purity. As to price, that comes down to what you think it will sell for. I like old European gold coins and have paid anywhere from -5% to +20% of spot price. They minted nearly 5.2 million of these so whilst not rare, it is uncommon but it comes down to finding a buyer who wants it at a price you are both comfortable with. If you're not sure, you could always auction it off or just set the price at spot +xx% and see how you go.
https://en.numista.com/catalogue/pieces21444.html
Thank you SteelHand, great info. I wasnt aware it was 0.9 and not 999, however thinking about it it would need to have an alloy mix for greater durability, such as Krugerands and Buffalo's.
And thanks for the link to numista site, could well be be handy in the future.
Of course, when you happen across a coin like this you hope they only minted 10 and it was the last one in existence worth millions, LOL.
Cheers
Strawman