By Jim Porter
What a U.S. Silver Eagle $1 coin might be ”worth” depends on four things;

U.S. Proof $1 Silver Eagle
1.) Is your Silver Eagle an “Uncirculated” coin or a “Proof” coin? Uncirculated coins are generally used as a bullion investment, and are worth around the value of 1 ounce of silver as described in (2) below. Proof Eagles have a mirror-like surface, and carry a numismatic value in addition to their intrinsic value, so are worth quite a bit more depending on the year issued. Your 1998 Proof Eagle is worth about $40, yet your Uncirculated 1998 Eagle is only worth about $16 (7/09). Your 2006 Proof Eagle can be worth as much as $295 (20th Anniversary 3-Piece Set), $210 (Reverse-Proof Coin) or as little as $44 (normal proof coin).

U.S. $1 Uncirculated Silver Eagle
2.) The bullion “value” is usually the HIGH price that one uses to set the standard base for the actual bullion coin. You can’t expect to go to your local coin shop and pay this “value-based” price for an ounce of silver, because ALL dealers charge a substantial markup on each coin, based on demand and availability. Neither can you expect to sell your ounce coin for this price. If silver bulliion is worth $17.52 an ounce (http://silverprice.org/), you might expect to pay about $19 per ounce coin. Yet, if the same day you try to sell that same coin back to the same coin shop you bought it from, you can expect to get between $13 and $15 for it. Bullion price quotes are only a guideline for your Silver Eagle Coin’s true “buy” or “sell” value.
3.) “Anything is only worth what people will pay for it.” You might maximize your sale by selling your coin in an online auction like EBAY, but it more than likely will be a “loss” to you unless you wait until the price of silver increases at least $5.00 an ounce (from your “buy” price) before selling it. What the coin and bullion market will reflect for your Silver Eagle’s value depends on supply and demand, like anything else of value.
4.) Condition and Grade play a large role in determining value. Certain Proof Silver Eagles in the 1986 to 2009 run have premiums because they have lower mintages and are rarer because of this (1993, 1994, 1995, 1996, 1997, 2006 Reverse Proof and 2008-W). Similarly, certain Uncirculated Silver Eagles have a premium value because of lower mintage numbers and less apparent availability (1986, 1992, and 1996). The mintmark can also determine rarity and value of Silver Eagle Coins based again on mintage numbers and availability (The “W” mintmark, West Point, for 2006, 2007 and 2008 coins adds a premium).
Some Silver Eagle Bullion coins have found their way into general “circulation”, and have lost some of their value for not having been handled by cotton-gloved fingers by their edges only. You can expect to get less for these “circulated coins” when you try to sell them, but also, you might get a better purchase price on them at coin shops and shows when buying them, as they no longer carry the premium as a numismatic collectable.

"Morgan" Silver U.S. $1 Coins 1878-1921
Although the Silver Eagle is considered to be an official U.S. $1 “Legal Tender” coin, most collector’s do not consider it to be a “silver dollar”. The most famous silver dollars were the Morgan Dollar and the Peace Dollar. The Morgan Dollar was designed by George T. Morgan and was minted from 1878 to 1921. The Peace Dollar (below) was designed by Anthony de Francisci and was minted from 1921 to 1935. As a bullion coin, these contain about 0.7 ounce of silver, and you might expect to pay between $16 for a common date “circulated” condition coin (GOOD to about FINE), and $30 for a common uncirculated coin. (Silver is about $17 an ounce today, 11/12/09)

U.S. "Peace" Silver $1 Coin