Why do gold coins still have denominations?

Obviously, I can’t buy a $50 gold coin, say an American Buffalo, for $50 as the gold is worth more than that. So, why are denominations placed on gold coins in the first place?

To make them “legal tender.” It makes them more acceptable, even thought the gold value is the main component.

To expand on my comment–when the U.S. decided to first offer gold “coins” to the citizens (ca. 1980, IIRC), they had no denomination, but were simply one ounce of gold and one half ounce of gold. Today, we buy them for less than the gold content, as people don’t seem to want to rebuy them as a gold coin. They prefer to buy something more recognized such as the American Gold Eagle, the Canadian Gold Maple Leaf, etc.

In some places I believe it makes a difference to sales tax. Legal tender is generally not subject to sales tax, bullion coins may be.

Depends on the place of course, and where the coins are from.

ETA: Also it puts a lower bound on the possible value of the coin. If a coin’s denomination is $200, it still retains a value of $200 even if the value of its gold drops below that. (Whether or not that’s ever likely to happen is another matter).

Hmm. Theoretically, then, could I take my million-dollar gold coin and use it as regular money for a down-payment on a condo in Toronto?

Well, as it is apparently worth nearer $2 million, they would be fools not to accept it.

Except, it’s worth about $4.5 million right now, gold value.

Great! It’ll pay for the parking spot as well!