If you mean a dual dated 1776-1976 Eisenhower Bicentennial Dollar, only the "S" mintmarked proof and special collector's coins are 40% silver. None of the business strikes are worth more than $1.00. They do have retail values of $1.10-$3.00 depending on the grades but no dealer will buy most of them for more than a dollar
The Melt Value of a 40% silver Ike dollar is $10.00 with silver at $32.20 per ounce.
Its worth 1 dollar in the stores, but as of April 21, 2010 the melt value of the coin is approximately $5.72
The current metal value is 19 cents.
As of today $14.00 is current MV for US silver dollars
If silver is at a spot price of $37.90 per oz a peace dollar would have a melt value of $29.32.
Without a date it is impossible to tell. These coins are usually not worth much more than their silver melt value. Their current silver melt value is $27.35 as of late February 2012.
It is made of 40% silver and has a melt value of about $2.50 as of 08/2008
The last year before 1964 that silver dollars were minted was 1935, and they were 90% silver. The melt value at present is about $24.
A 1921 Half Dollar is 90% silver. It has a melt value of somewhere around $12. The related link below has more information.
As of June 4 2011 the melt value of a 90% silver half dollar is $13.13. See the related link below for a updated price. After clicking the link click on silver melt values at the top right of the page. Then scroll down to the link that says 1964 Kennedy half dollar.
Current MV of any 90% silver half dollar is $7.64. Spot price of silver is $21.12 at this time.
As of May 24 2011 the melt value of a 1935 half dollar is $13.04. This price reflects silver at a spot price of $36.04 per oz. This value will change as the price of silver changes. This price will be the same for all walking liberty half dollars.
If silver was at a spot price of $37.90 per oz all peace dollars have a melt vale of $29.32.