Low mintages: The 1973-S 40% silver business strikes and Proof coins have the lowest mintage figures of all the 40% silver Eisenhower dollars. Because of this, the 1973-5 Proof 40% silver Eisenhower dollar is generally regarded as the key date in the series.
Availability: Eisenhower dollar specialist Dave McHenry noted this:
1973-S: As these 40% silver coins were sold directly to collectors, good quality specimens are not hard to find today. Most are in higher grades, and MS-64 and MS-65 pieces are not difficult to find. The Proofs are usually found in higher grades as well. Around 1979, these Proofs wholesaled for $140 or more, and now in 1993 they are worth less than $20 each, and, seemingly, are very underpriced.
Certification: As of January 1993,PCGS has certified 354 MS-65 specimens, 965 MS-66 coins, 353 at the MS-67, and 10 pieces at the MS-68 level, with none higher. Those who like MS-67, MS-68 and other high technical grades can have a field day with these coins. The only problem is this: No one has ever defined the difference between, say, MS-67 and MS-68.
1. 1973-S silver clad. A few are known with doubled obverse die, plainest at the motto.
1. 1973-S silver clad.
Enabling legislation: Act of July 23, 1965 (clad metal), Act of December 31, 1970, and others.
Weight (silver clad): 379.512 grains (tolerance 4%); outer layers of .800 silver, .200 copper bonded to inner core of .209 silver, .791 copper.
Melt-down (silver value) in year minted: $.40.
Dies prepared (approximate): Obverse: 19; Reverse: 10.
Business strike mintage: 1,883,140.
Comment on availability, MS-65: or betters Moderately scarce, but available.
Comment on availability, MS-64: Slightly scarce.
Comment on availability, MS-63: Readily available.
Comment on availability, MS-60 to 62: Readily available.
Comment on availability, VF-20 to AU-58: Circulated examples are seldom encountered, as the coins were sold at a premium.
Characteristics of striking: Generally well struck with good lustre.
Known hoards of Mint State coins: No hoards are known of this date, although small quantities are readily available.
Dies prepared (approximate): Obverse: 405; Reverse: 290.
Proof mintage: 1,013,646.
Comment on availability, Proof-65 or better: Most extant coins are in this category.
Comment on availability, Proof-64: Scarcer than the preceding (for now, but give collectors a chance to mishandle their coins).
Comment on availability, Proof-63: Still scarcer. Comment on availability, Proof-60 to 62: Scarcer yet.
Comment on availability, less than Proof-60: Very few exist.
Demand bid up these coins to high levels in the late 1970s, after which interest subsided and prices fell.