None of the modern US gold bullion coins are worth millions.
The English Gold Florin was minted under Edward III for only one year, 1344. Any of these coins existing now are museum pieces worth millions of dollars.
The modern US Saskatewan dollar is not gold. The USA and many other countries have minted gold coins for thousands of years. The US made millions of gold dollars in the 1800;s and many are still available. Most you see today though are counterfeits
20 dollars
There were eight coins ... 1 cent 5 cents 10 cents 25 cents 1/2 dollar 2.1/2 dollars (gold) 5 dollars (gold) 20 dollars (gold)
Hitting the lottery, finding a gold mine.
hundreds of millions of dollars
All the 2000 to date dollar coins are NOT gold, they are made from brass, that's what gives them the gold color.
Ancient roman coins can vary widely in value, from US$2 or US$3 for a circulated common copper to tens (or even hundreds) of thousands of dollars for very rare uncirculated gold or silver coins.
Those coins are still worth one dollar, and they contain no gold.
7 millions dollars
Today, each gold coin has its own value. In order to give an accurate answer to this question the denomination and date and condition of each of the coins is needed.
US gold dollar coins were minted from 1849 to 1889. They were smaller than dimes and were never very popular due to their size. The new Sacajawea and Presidential "golden" dollars introduced in 2000 and 2007 respectively are only gold COLOR, not real gold. They're made of manganese brass. Even though some people mistakenly believe the coins contain gold, the metal is far too expensive and volatile in price to use in circulating coins today.