Doug Winter: The following information is from my eBook on Type One Liberty Head Double Eagles at http://doubleeaglebook.com/
The 1857 has shed its status as a common date but it is still lightly-regarded outside of Type One specialists. It is clearly less scarce than the 1855 and 1856, but it is a much harder issue to locate than the 1851-153 Philadelphia trio.
STRIKE: This is an issue which is not often seen with a sharp strike. The obverse tends to show good overall detail on the hair with some individual definition noted on the strands at the top of Liberty’s head. The lower part of the obverse is weaker than the rest of the coin, with the date and the first star sometimes not well-impressed at all. The reverse tends to be better struck with a sharper center than on the obverse. The upper portion, which corresponds to the lower portion of the obverse, can sometimes show weakness. Many have a network of fine die cracks on the reverse.
SURFACES: This is a date that is very hard to find with good surfaces. Most 1857 double eagles show deep, detracting marks on the surfaces. It appears that the 1857 saw extensive use in circulation and not many have turned up in hoards, making higher grade pieces very difficult to locate.
LUSTER: The luster on higher-grade pieces tends to have a satiny texture. This luster is often impaired by a combination of extensive abrasions and prior cleaning(s).
COLORATION: Very few 1857 double eagles are seen with natural color as most have been brightened at one time. The few seen with natural color are either medium yellow-gold or a light rose-gold shade.
EYE APPEAL: The 1857 double eagle shows below-average eye appeal. This is due to a combination of factors. Many are not well-struck on the lower obverse and show numerous marks on the surfaces. The luster and color are frequently impaired. 1857 double eagles which are “CAC quality” are much harder to find than people realize, and are worth a significant premium above typical quality examples.
INTERESTING VARIETIES: All 1857 double eagles have a large date which is similar to that found on Large Cents of this year. No significant varieties are currently known.
PROOFS: There are no Proofs currently known to exist. It is possible that a small number were struck as Proofs are known for all of the other gold denominations of this year.
HOARDS: There were 20 examples in the S.S. Republic, including seven in Uncirculated. Only two were recovered from the S.S. Central America treasure.
BUYING TIPS: This is a date worth stretching on as most collectors are not aware how scarce a choice, higher-grade 1857 double eagle actually is. Price levels remain reasonable within the parameters of this series.
AUCTION RECORD: The current auction record is $47,000 which was set by Heritage 8/13: 5899, graded MS63 by PCGS.
FINEST KNOWN: I haven’t seen this coin in person but the finest known is likely the PCGS MS64 which was last sold as Stacks 10/08: 1464; it realized $40,250 and was then graded MS64 by NGC. The second finest is a coin I sold to a New England collector and it is ex Heritage 2013 ANA: 5899. It realized $47,000 and was graded MS63 by PCGS.
TOTAL KNOWN: 900-1200+
Very Fine: 300-500
Extremely Fine: 300-400
About Uncirculated: 170-250
POPULATION FIGURES: As of the beginning of 2015, PCGS has graded nine in MS60, nineteen in MS61, 28 in MS62, three in MS63, and one in MS64 for a total of 60 in Uncirculated. NGC has graded 10 in MS60, 18 in MS61, 15 in MS62, one in MS63, and two in MS64 for a total of 46 in Uncirculated. They have graded seven in Uncirculated from the S.S. Republic. These figures are way inflated, especially in MS61 and MS62 grades. CAC has approved a total of six Uncirculated examples, two in MS60, two in MS61, and two in MS62.
PERFORMANCE SINCE 2002: In the current market, a choice About Uncirculated example of this date (equivalent to AU55) would sell for $3,500-4,000. The same coin back in 2002 would have sold for $1,000-1,250. In the current market, an average quality Uncirculated example of this date (equivalent to MS61) would sell for $8,000-9,000. In 2002, the same coin would have sold for $3,000-4,000.
COMMENTS: My choice for most undervalued Type One double eagles are the 1855, 1856, and 1857. Considering that a high-end AU example can still be purchased for around $4,000 makes the 1857 a good value within this series.David Akers (1975/88): The 1857 is a very scarce date that is comparable in overall rarity to such other Type I P-Mint issues as 1855, 1856, 1858, 1863 and 1864. (However, it is not as "impossible" to obtain in Unc. as the 1863 and 1864.) It is considerably rarer than any of the 1850-1854 dates from the Philadelphia Mint. Most available specimens grade VF or EF although AU's and an occasional unc are also seen from time to time. Choice or gem quality uncs are rare but do exist; I have seen several at those levels.