How much is a E Pluribus Unum 1898 coin worth?

American 1898 CoinsThat depends on which coin it is - you could have a US nickel, quarter, half, or dollar with that motto on it. Then, the mintmark will make a difference. The nickels won't have one since they were only minted in Philadelphia, but the others could also have an S for San Francisco or O for New Orleans. And probably the biggest factor is the condition. In high uncirculated condition, they could be pretty pricey and if worn out or damaged any would be nearly worthless.

You can find an online retail price guide here: http://www.numismedia.com/fmv/fmv.shtml

Also please note that ALL U.S. coins bear the motto "E Pluribus Unum" ("From many, one") so this is not a distinguishing characteristic of a coin. The denomination, date, mint mark, and condition are the most helpful characteristics to start with.