Roman gold coins are worth their weight in gold! In fact, in many cases they are worth a lot more.
The Romans used gold, silver and copper coins in their monetary system. Gold coins were mainly used by administrators or wealthier merchants. The silver and a copper alloy were used by ordinary merchants and the people of Rome and the Roman Empire.
People would also often convert their earnings and life savings into gold coins and hide them.
The gold coin, or 'Aurei' as it was called then, was usually around 95 percent pure gold. A legionnaire would earn about 4 a week. One Aurei would buy 400 litres of cheap wine or 200 pounds of flour.
Roman gold coins usually had the head of the Emperor or Caesar at the time the coin was struck and most Roman gold coins were struck at the Constantinople Mint.
There are many many issues of coins depicting various Emperors. Most are rare and command a high value well over the value of the gold content.
Roman coins are usually weight by gram. They can be from a couple of grams upwards.
For example a Honorius, 22 January 393 - 15 August 423 A.D. Extra Fine weighting 4.449 grams with Honorius on both sides would fetch around 700-800 dollars US.
Because collecting Roman gold coins is very much a specialized activity, one needs to ensure that one is dealing with a reputable dealer who knows and understands Roman gold coins. In the field of coin collection or numismatics, Roman gold coin collection is somewhat more specialized.
Roman Gold coins is an excellent site to go to join a Roman gold coins collectors group or Forum. There is a wealth of information there and one can get thoroughly acquainted with this fascinating hobby of Roman gold coin collecting!