If you mean a 1988 Silver Eagle only Proof and bullion coins were struck in that year.
From 1986 to 1992, proof Silver Eagle coins were minted at San Francisco and these coins bear the "S" mintmark and have a current retail value of $20.00.
Bullion Silver Eagle coins dated 1988 were also struck at San Francisco but do not have mintmarks, the value of these coins depends on the spot price of silver at time of sale. As of today it's about $17.50.
Be advised that a (half pound silver coin) may really have have 6 troy oz, not 8 avp ounces.
In 1988, silver was priced at about $6.00 per ounce -- today it's about $17.00 per ounce.
Historical charts and info can be found at :
www.kitco.com
$1.00
09/01/08, the price of one troy ounce of silver was $13.58 & on 09/30/08, the price of one troy ounce of silver was $12.96
The price of silver is generally given per troy ounce. There are 32.150747 troy ounces in a kilogram. The current price of silver (22 May 2008) is $17.960 USD per ounce, so that would make the value $577.43 USD per kilogram.
The value of gold on July 7, 2008 was $843 per ounce. ($924.90 or £570.0 per troy ounce.)
Silver was $17.68 an ounce, according to Engelhard Commodities.
A Barber Quarter weighs 6.25 grams and is 90% silver. This equates to Actual Silver Weight (or "ASW") of 0.1818 troy ounces. As of December 5, 2008 (with silver at $9.48/troy ounce), that is a "melt value" of about $1.72. Depending on condition, however, the numismatic value (that is, the value to a collector) is likely quite a bit higher.
4-23-11>> The only US coin dated 2003 with the Walking Liberty design is a Silver Eagle Bullion coin. The value of the coin is tied to the spot price of silver at time of sale, today it's $46.61 per ounce.
5-10-11>> The coin is ounce of pure silver and the value is tied to the spot price of silver at time of sale and it varies, as I type this, the coin is worth $38.22
$49.45 per troy ounce, reached in 1980.
At very least, a silver coin will always be worth scrap value. So check the value of silver against the weight of the coin. It is likely a collector will pay more than the scrap value of the coin, even if not by much. Since the coin is not particularly old I would estimate as of March 2008 the coin to be worth around £10.
About $17 or $18, or more if silver rises dramatically in price (as of January 30, 2008, silver is $16.76 per troy ounce and the Morgan silver dollar has an Actual Silver Weight of 0.7734 troy ounces, giving it a "melt value" of about $12.96). Note that there would be no "P" mint mark - coins produced in Philadelphia at that time had no mint mark.
"ASW" means "Actual Silver Weight", and refers to the weight of the silver (in troy ounces) in the coin. To get the "melt value" of a silver coin (that is, the value of the silver in the coin melted down, without regard to any numistmatic value the coin might have), you would multiply the ASW by the current value of a troy ounce of silver ($19.92 as of March 2, 2008). By the way, the concept of "AGW" and "APW" (for "Actual Gold Weight" and "Actual Platinum Weight", respectively) is exactly the same.
Its value is tied to the current spot price of silver. As of 07/2008 that's about $18.