Ron Guth:
The 1904 Half Dollar is a better date but it is common enough that it cannot be considered underrated. It is much more common than the 1903, including in Mint State. In MS65 and better, it is twice as plentiful as the 1903. All things considered, the 1904 is an excellent value for the type collector because it appears on the market less frequently than common dates such as 1912-D, 1913, 1914, and any of the 1915's, yet it sells for only a slight premium. Plus, most 1904's are well-made and nicely detailed.