By 1873, the Two Cents denomination had run its course. Mintages had declined precipitously each and every year since the inaugural year in 1864. Apparently no one cared for the denomination except the fewer than a thousand collectors. In fact, the only Two Cents struck in 1873 were Proofs, and the only reasons they were made was to satisfy the limited collector demand and to make some extra profit from the sale of minor proof sets.
1873 Two Cents come in two varieties: Open 3 and Closed 3. The Closed 3 (which was not really closed) looked too much like an 8, so the Mint opened the gap in the 3 to prevent any confusion. The Closed 3 is approximately 2.5 times more common than the Open 3. Gem Proof 1873 Two Cent pieces -- of either variety -- are quite scarce, and any Open 3 in PR66 or better is extremely rare.