How much is a 1883 e pluribus unum silver eagle worth?

Please see the Related Question because the coin isn't a silver eagle. "Silver eagles" are modern bullion coins containing 1 oz of silver and sold by the Mint to collectors and investors. What you have is a $1 coin called a Morgan dollar minted for use in ordinary commerce. At the time the price of silver was controlled and the coin was in fact worth exactly one dollar.

Also, All Morgan and Peace dollars carry the motto E Pluribus Unum as do most other U.S. coins so that's not a distinguishing piece of information.