Currently, the Peace Silver Dollar, is the best 90% silver dollar buy. Unlike the Morgan Dollar at $30+, you can still obtain common date Peace Dollars for under $30 and get better deals buying in rolls or bulk. However, the mint marked and mint state grade Peace have gained ground on the Morgan.
A few facts lead to this up-swing in premium: Peace Dollars were once not very collectible and because of the high mintages of the 1922, 1923, 1924, 1925, they where regarded as the lesser of the two major silver dollars of their time. Recently, last 10 years or so, collectors have come to appreciate the Peace more, and realize how low some of the S and D mint marks actually are.
In addition, some of these mintages are much lower than the Morgan Dollars, and MS65 Peace Dollars are more difficult to obtain than their Morgan counterparts.
It use to be that everyone hoarded and desired the 1921 and 1928 Peace, but from the list above, you can see thisd caused some of the other dates and mints to be more rare in MS. Of all the dates that are breaking records in high grades, not all of them have been dated 1928, 21 or even 34-S as some might think. Below I have an image of this beautiful 1925 MS68 Peace Dollar, courtesy Heritage Coin Auctions, and you can click on the coin to see a larger image.
The above list is the Top Ten sold values for Peace Dollars and the number one coin on this list is the most this coin type, denomination and date has ever sold for publically.
These values do not apply to raw coins or coins in any other holder; these values only apply to coins graded and certified by PCGS (Professional Coin Grading Service) or NGC (Numismatic Guarantee Corporation). Also, a few of these coin holders have CAC (Certified Acceptance Corporation) stickers and this is considered further assurance that the coin is the grade and condition stated on the holder's label.
You can't buy or sell Peace Dollar United States coins for the prices listed in this website unless they're in the same grading company holder, same grade, variety and condition, even then there's no guarantee your Peace Dollar will sell for the same value.
If you want to learn the value of your Peace Dollar then you must know the coin's grade, condition, and if it's authentic. You do this by taking your coin to a reputable coin dealer or sending your coin to PCGS or NGC (fees do apply with these services). If you're not interested in sending your coin to a third party grading service then you should do some research and find a reputable coin dealer instead. I recommend a PCGS Coin Dealer since at least three of their piers have to vouch for them to be a PCGS Dealer.
If you can't find a PCGS Coin Dealer then look for local ANA members or coin clubs. In the mean time you can get an idea of your Peace Dollar's value and grade by visiting CoinHELP! website.