The price of bullion is given as the cost per Troy ounce. Gold often sells for over a thousand dollars per Troy ounce. This makes buying an ounce of gold prohibitive for many people. Some mints produce gold bullion coins in fractional sizes, or coins weighing less than one Troy ounce.
While these mints do not release bullion directly to customers, one can contact them to determine the sizes of gold and silver coins made by them. You can also get fractional gold coins online from reliable dealers.
The common sizes for gold coins are one, one half, one fourth, one-tenth, one-twentieth, and one twenty-fifth of a Troy ounce. Not every mint makes all of these size coins, but these are the more common sizes for fractional gold coins. There are, of course, exceptions.
For instance, there is a rare one-fifteenth Troy ounce gold coin that is the product of the Royal Canadian Mint makes one-thirtieth Troy ounce gold coins, although not as bullion.
As a rule, the less expensive a coin, the greater percentage over the price of the precious metal one would expect to pay for a coin. The mint must recover the cost of production of the coin, which is about the same regardless of the coin's weight.
Yet, if one wants to own bullion, one can buy bullion inexpensively. Fractional coins make owning bullion coins possible for more people than would otherwise be able to afford to own bullion coins.