who give them the price?
is there only one like it all over the world?
Prices for rare coins are set during auctions. You have to know what people are willing to bid before you set a price. As this coin has never been on an auction, it's hard to guess. But one can estimate. Other gold coins which only exist in one exemplar has been sold on auctions. It is not unlikely this one would be in that price range. Then we're talking about $10 000 000. Probably more as it was a few years since last time and because we tend to see new records each time something unique comes for sale.
Only one, yes. It's a US coin, no other country can make them. If they do, it's called forgeries. And forgeries are not valuable.
ST rank 36 (best 1) - 14 wins, 3 titles (Paris 2014, Madrid + Vienna 2015) YE rank: 16 - 1 - 22 - 47
TT singles rank 108 (high 29), Titles: Memphis 2015.... TT doubles rank 74 (high 19). Titles: Quito 2015 (w/scarecrows), Basel 2015, Barcelona 2016 (w/Björki), Estoril 2016 (w/Taz Warrior), Kitzbühel 2016 (w/tal20)
Detailed Tennis Tipping results
Member of Tennis Tipping board and Suicide Tennis board