Like many of the late date Three-Cent Silvers, the 1869 has a tiny mintage and it is rare in all grades. Proof examples are easier to locate, so some collectors, especially date collectors, will accept a Proof as a substitute for the rare Mint State example. However, purists stick with the true Uncirculated examples, placing extra price pressure upon them.
In terms of rarity, the 1869 correlates closely to the 1867, which has a similar mintage and survival rates. In fact, the listings in the PCGS Population Report, at least in Mint State, track each other almost identically.
The typical 1869 Three Cent Silver is usually well struck and will come either frosty or Prooflike. The finest examples certified by PCGS include four MS66s and none finer.