The following information is from my eBook on Type One Liberty Head Double Eagles at http://doubleeaglebook.com/
The 1860-S remains similar to the 1859-S in overall and high-grade rarity. There are a few more choice (Mint State-62 to Mint State-63) of the 1860-S, but this remains a rare date in this range.
STRIKE: As with many of the San Francisco double eagles from this era, the 1860-S is not an especially well struck issue. On the obverse, the hair tends to be weak with little definition noted on the curls or at the top of the head. The bun tends to be weak as well. The stars on the obverse are sharp with many displaying full radial lines. On the reverse, the wing tips are soft even on high grade coins but the rest of the detail is sharp. Many have fine die cracks through the lettering.
SURFACES: The majority of 1860-S double eagles are extensively bagmarked on both the obverse and the reverse. There are some with relatively clean surfaces but these are difficult to locate. I have seen a number which have some minor roughness in the planchet or with mint-made spotting.
LUSTER: The luster is soft and frosty and shows a somewhat grainy texture. The quality of the luster is similar to that seen on the 1859-S and it is superior to that seen on the 1861-S and 1862-S double eagles.
COLORATION: The natural coloration ranges from medium orange-gold to deeper rose-gold to a medium green-gold hue. It has become difficult to locate an 1860-S with nice color as many have been cleaned or dipped.
EYE APPEAL: This date has average eye appeal. Most are softly struck and show numerous abrasions on the surfaces. The luster and color tend to be nice enough on higher grade pieces that the fussy collector can overlook the quality of the strike and the surfaces. A CAC quality example should be locatable but it will command a 15-25% premium over a typical 1860-S.
INTERESTING VARIETIES: All have a medium S mintmark. There are no significant varieties.
PROOFS: No proofs were struck.
HOARDS: There were a total of 63 examples in the S.S. Republic. These were mostly grade AU55 to AU58 by NGC. There were 18 pieces in the S.S. Brother Jonathan treasure. These were mostly in the EF40 to AU50 range.
BUYING TIPS: The rarity of this issue in properly graded Mint State-60 and higher is underestimated as many collectors mistakenly believe that the 1860-S is a shipwreck date. Any Uncirculated example, especially with natural color and better than average surfaces, is rare.
AUCTION RECORD: The current auction record for this date is $29,900 which was set by Heritage 1/12: 5037, graded MS63 by PCGS.
FINEST KNOWN: The finest known is a PCGS MS64 owned by a prominent Midwestern collector. This coin is plated on Coinfacts.com where it is also believed to be the single finest example of the date.
TOTAL KNOWN: 1400-1900+
Very Fine: 400-500
Extremely Fine: 700-9000
About Uncirculated: 280-470
POPULATION FIGURES: As of the beginning of 2015, PCGS had graded 8 in MS60, 12 in MS61, 11 in MS62 and one each in MS63 and MS64 for a total of 33 in Uncirculated. NGC had graded 3 in MS60, 14 in MS61 and five in MS62 including three in Uncirculated from the S.S. Republic for a total of 22 in Uncirculated. These figures are inflated, especially in MS61. CAC has given approval to a lone Uncirculated example, an MS62.
PERFORMANCE SINCE 2002: In the current market, a choice About Uncirculated example of this date (equivalent to AU55) is worth $4,000-5,000. The same coin in 2002 was valued at $2,000-2,500. In the current market, an average quality Uncirculated example of this date (equivalent to MS61) is worth $13,000-15,000. The same coin was worth $4,500-5,500 in 2002.
COMMENTS: The 1860-S double eagle is a scarce and underrated date in higher grades. I believe I overstated the number known in Uncirculated when I wrote the first edition of this book in 2002. There are currently just two pieces known which have been graded higher than MS62 (and one of these, the PCGS MS63, has a large stain on the obverse) with probably no more than a half dozen properly graded pieces known in MS62. An outstanding example of this date can still be purchased for less than $20,000, and I believe that this is an excellent comparative value within the context of the Type One series.
David Akers (1975/88):
The 1860-S is one of the rarest Double Eagles from the San Francisco Mint. It is not as rare as the 1861-S Paquet or the 1866-S No Motto, the two rarest S-Mint issues, but it is in the second rarity level along with the 1854-S, 1861-S, 1862-S, 1864-S, 1866-S Motto, 1867-S and 1868-S. When available, the typical 1860-S is only VF or EF. Strictly graded AU's are very scarce and uncirculated specimens are rare. In choice or gem uncirculated condition, the 1860-S is virtually impossible to obtain. Most specimens are well struck and every one I have seen was frosty.