The value of gold coins used as bullion is global, though additions such as taxes can change the value from country to country. Gold coins are generally priced according to their weight following the spot price of gold in the global market. This spot price is based on the supply and demand of gold, which is used primarily for decorative and industrial purposes.
Gold coins produced as bullion often have a premium attached to the price. This premium covers the cost of producing and certifying the coins. Premiums can change depending on the coin dealer, with added costs the further from the creation source. For example, a gold coin purchased from a smelter is less expensive than that same coin purchased from a coin dealer.
Collectible gold coins have a value set on the demand for the coin. Demand for a collectible gold coin is based on the rarity of the coin, the coin's condition and the interest collectors have in that particular coin type. The weight of the coin also has an effect on the coin's value, as does its age. Globally, the price paid for a collectible coin remains stable. Like bullion coins, however, there can be a cost to selling collectible gold coins due to taxes, which changes from country to country.