The following information is from my eBook on Type One Liberty Head Double Eagles at http://doubleeaglebook.com/
After three consecutive years of tiny mintage figures, production of double eagles at the New Orleans mint increased in 1857. While only 30,000 were struck, this was more than twice as many as had been made from 1854 through 1856. This shouldn’t give the impression that this is anything but a scarce issue as it is, in fact, very difficult to locate and it is comparable in overall rarity to the 1858-0.
STRIKE: The strike on most 1857-O double eagles is below average. The obverse shows weakness on the curls around the face and below the ear of Liberty. Weakness is also noted on the top of her head and the bun. The stars show some radial line detail, but the denticles can appear to be weak. The reverse is often weak on the wing and tail feathers and the neck feathers.
SURFACES: There are not many 1857-O double eagles that have clean, non-abraded surfaces. This was an issue which appears to have seen heavy commercial usage and most have been beaten-up as a result. In addition, many have been cleaned and show major hairlines as a result. Others have small mint-made imperfections such as grease stains, planchet chips, or roughness. All 1857-O double eagles display raised die rust near the ear of Liberty. On low grade coins this may not be visible.
LUSTER: The luster on this issue is better than one might expect, and higher-grade pieces may either be frosty or semi-prooflike. A small number of nearly full prooflike examples are known including two Uncirculated pieces designated as “PL” by NGC. It remains very difficult to locate a circulated 1857-O with unimpaired luster as most have been cleaned or dipped.
COLORATION: The natural color is medium to deep green-gold. Many are now unnaturally bright from having been cleaned or dipped. Pieces with attractive natural color do exist and these tend to bring a strong premium.
EYE APPEAL: The eye appeal is below average. Most 1857-O double eagles are not well-struck and they display heavy abrasions on the obverse and reverse. It isn’t impossible to find a CAC-quality piece, but as with most of the scarcer New Orleans double eagles, such coins are truly rare.
INTERESTING VARIETIES: Only a single variety is known.
PROOFS: There are no proofs this year.
HOARDS: There were four examples in the S.S. Republic, including three in Uncirculated. In the early 1990’s, a group of approximately 40-50 pieces grading VF to AU were found in Europe. These were quickly absorbed by collectors.
BUYING TIPS: For collectors who can’t afford the big-ticket New Orleans double eagles, the 1857-O (along with the 1858-O) tends to be their biggest expenditure in the Type One series. A collector who is patient should be able to find a decent quality example, but should be prepared to stretch for such a coin if and when it becomes available.
AUCTION RECORD: The record price was set by Heritage 1/11: 5251, graded MS62 by NGC and now in an MS63 holder. It brought $172,500.
FINEST KNOWN: The finest known is the PCGS MS63 in the Crawford collection. It is from the Bass III sale and was earlier in the Kaufman collection. The second finest is an NGC MS63 which is ex Heritage 2011 FUN: 5251 where it sold for $172,500 as an NGC MS62.
TOTAL KNOWN: 200-250
Very Fine: 70-100
Extremely Fine: 70-80
About Uncirculated: 55-63
POPULATION FIGURES: As of the beginning of 2015, PCGS has graded just a single coin in Uncirculated, an MS63. NGC has graded one in MS60, one in MS60PL, one in MS61PL, two in MS62, and one in MS63 for a total of six in Uncirculated. This includes three coins from the S.S. Republic. CAC has approved only one Uncirculated example, graded MS62.
PERFORMANCE SINCE 2002: In the current market, a choice Extremely Fine example of this date (equivalent to an EF45) would sell for $7,000-9,000. In 2002, the same coin would have sold for $2,000-3,000. In the current market, a choice About Uncirculated example of this date (equivalent to an AU55) would sell for $15,000-17,500+. In 2002, the same coin would have brought $7,500-10,000. This date has performed well in lower grades but not as well in About Uncirculated. I attribute this to the fact that the grading services continue to put inferior quality 1857-O double eagles in AU55 holders, and if quality standards would tighten you would see this date quickly shoot up in price (as well as in AU53).
COMMENTS: A lot has happened with the availability of higher-grade 1857-O double eagles since the first edition of this book was published in 2002. A small group of high-grade pieces were found on the S.S. Republic, and this means that at least three lucky collectors are now able to own an Uncirculated 1857-O. The only one of these three to sell at public auction was an NGC MS60 which realized $46,000 as Heritage 3/08: 1638. The Heritage 1/11: 5521 coin from the Miller collection was an impressive coin which I was not previously aware of. Along with the MS63 Bass coin, these are not only the two finest known for the date but are two of the finest New Orleans double eagles, period.
David Akers (1975/88):
The 1857-O is a rare date in any condition and most known specimens grade only VF or EF. There are at most a mere handful of strictly graded AU coins in existence and I have personally examined only one unc, the very choice Kaufman specimen now in the Bass Collection. Overall, the 1857-O is slightly less rare than the 1858-O and is perhaps just a bit more rare than the lower mintage 1861-O. It is also decidedly more rare than the O-Mint issues from 1850 to 1853. The typical 1857-O is semi-prooflike or prooflike.