The 2000-S Sacagawea Proof Dollar is fairly common. It has a mintage of over 3.2 million. Other examples in the series have mintages closer to 1 million and are much scarcer than the 2000-S Proof Sacagawea Dollar.
Most examples were struck well ranging from about PR68-PR69 Deep Cameo condition. Perfect PR70 Deep Cameo examples were a little harder to find but enough examples are out there to keep prices very affordable for just about any collector.