Varieties:

Open 3

Closed 3

Notes:
The finest Proof "Closed 3" Brown example graded by PCGS is a single PR-66BN.

The finest Proof "Closed 3" Red-Brown examples graded by PCGS are 14 PR-66RB's.

The finest Proof "Closed 3" Red example graded by PCGS is a single PR-67RD.

The finest Proof "Open 3" Brown examples graded by PCGS are 4 PR-65BN's.

The finest Proof "Open 3" Red-Brown examples graded by PCGS are 3 PR-66RB's.

The finest Proof "Open 3" Red examples graded by PCGS are 5 PR-66RD's.

Significant examples:
PCGS Proof 66 Red (illustrated above).  Ex - Superior Galleries' "Pre-Long Beach Sale", October 1-3, 2000, Lot 4180, illustrated, sold for $11,500.00, where it was described as follows: "1873 Open 3 PCGS Proof 66 RD Population: 7, with 0 higher. A fantastic coin to open with (the 1864 Small Motto in Proof 66 Red) and an equally desirable specimen to close this attractive series, a lovely full mirror Red 1873 with Open 3 in date. Bright with warm orange-gold to coppery red color, the fields and devices are utterly pristine. The strike, too, is "as you like it", from the motto to the shield, the legends and the wreath, everything crisp and bold. Two varieties were issued the final year, 1873. Two-centers are found with either a Closed 3 or an Open 3 in date. The Open 3's mintage (it is believed all were restrikes) has been estimated at 500 pieces in the Guide Book of United States Coins.  A short-lived series, Two-cent pieces circulated at first because of the Civil War coin shortage; but after the war, fewer banks called for this denomination, and mintage dwindled, coinciding with increased coinage of nickel 5c pieces. This was believed -- rightly or wrongly -- to reflect lack of public acceptance of the denomination. Accordingly, the Act of March 3, 1871 authorized the Mint to redeem and melt these coins. Large mintage of cents, 1873-76, in fact came from bullion obtained from wholesale melting of half cents, large cents, and 2c coins. By 1873, only Proofs were made for inclusion in the Proof sets; no business strikes came off the presses. The Coinage Act of February 12, 1873 decided to omit the denomination and it quietly faded from memory except for these few surviving examples. (Coin is housed in PCGS holder 4756644)"

Recent appearances:
PCGS Proof 66, Red.  Ex - Ira & Larry Goldberg Coins & Collectibles, Inc.'s "Benson Collection, Part I", February 16, 18-20, 2001, Lot 1465, "Closed 3", illustrated, sold for $6,325.00  Part of The Benson Collection purchased in the 1940s

NGC Proof-66 Red.  Ex - Bowers & Merena Galleries' "The Rarities Sale", January 3, 2001, Lot 73, "Open 3", illustrated, not sold

NGC Proof-66 Red and Brown.  Ex - Heritage Numismatic Auctions, Inc.'s "Philadelphia 2000 Signature Sale", August 6-7, 2000, Lot 6739, not illustrated, sold for $2,300.00

PCGS Proof-66 Red and Brown.  Ex - Bowers & Merena Galleries' "The Cabinet of Lucien M. LaRiviere, Part III", May 21, 2001, Lot 1372, "Open 3", illustrated, sold for $2,875.00  From the Bowers & Merena's Rarities Sale, August 1998, Lot 52

PCGS Proof 65, Red and Brown.  Ex - Ira & Larry Goldberg Coins & Collectibles, Inc.'s "Benson Collection, Part I", February 16, 18-20, 2001, Lot 1466, "Open 3, Restrike", illustrated, sold for $2,645.00  Part of The Benson Collection purchased in the 1940s

PCGS Proof-65 Red and Brown.  Ex - Heritage Numismatic Auctions, Inc.'s "Long Beach Signature Sale", May 31-June 2, 2001, Lot 6208, "Closed 3", not plated, sold for $2,185.00   From the Alex Highland Collection

Proof-64 Red and Brown.  Ex-  Heritage Numismatic Auctions, Inc.'s "October 2000 Long Beach Sale", October 5-7, 2000, Lot 6688, not illustrated, sold for $1,265.00, Previously offered in the Nov. 99 Santa Clara Sale as Lot 5114.

Proof-64 Brown.  Ex - Bowers and Merena Galleries' Robert W. Schwan Collection Sale, October 26-27, 2000, Lot 399, "Open 3", sold for $1,380.00

Proof-63 Red and Brown.  Ex - Heritage Numismatic Auctions, Inc.'s "Santa Clara Signature Sale", November 16-17, 2000, Lot 5165, "Closed 3", not illustrated, sold for $1,207.50

Proof-45.  Ex - Bowers & Merena Galleries' "The Cabinet of Lucien M. LaRiviere, Part II", March 15-17, 2001, Lot 1316, "Closed 3",  sold for $977.50

Sources and/or recommended reading:
"The PCGS Population Report, July 2003" by The Professional Coin Grading Service