What is the value of a 1988 roosevelt copper dime?
Any standard dime dated 1965 or later and taken from circulation is worth only 10 cents. However, if by "copper" you mean that one side of the dime is copper-colored and the other is silver-colored (nickel, actually), you may have what's called a lamination error. That happens when one side of the coin's cladding (the nickel-colored part) doesn't bond properly. This is considered to be a mint error and retails for 5 or 6 dollars.