What is the value of a 1964 D mint mrk penny in good condition?

Until you show me what makes it different than the other 3,799,071,499 1964-D cents, I'm going to have to say it is worth 1 cent. Actually, since it was made before they started using zinc instead of copper, it is worth about 2 cents as bullion, but it is illegal to melt it in the US.