Value of a 1863 2.5 dollar liberty head gold coin?

Answer 1

You ask about the 1863 quarter eagle but don't mention the "S" mint mark. If the coin is missing the mint mark it's counterfeit. Only the San Francisco mint struck quarter eagles in 1863 with a small mintage of 10,800 coins and most all were released for circulation which makes the coin very rare in Mint state condition. A well worn 1863s is about $420.00 retail, a coin with light wear is $3,200.00-$9,940.00 depending on grade. And mint state coins are $15,690.00+. If you actually have this coin, I suggest a third-party grading service