It depends on rarity and condition. Just like baseball cards, some coins are worth virtually nothing and others are worth a tremendous amount of money. It also depends on how the market perceives their value. The ancient coins market is identical to every other supply and demand market in the capitalistic world. You can buy coins on E-Bay for a dollar a piece. You can also find some that are not genuine on E-Bay. It doesn't necessarily cost you a lot of money to start collecting, but having said that, some coins have sold for upwards of one million dollars. I would say that a common coin that a serious collector would find desirable would typically run between $100-300.
