The 1925-S peace dollar is a relatively common coin, with a mintage of over 1 million. As such, it is not particularly valuable in circulated condition. An average-circulated 1925-S peace dollar is worth around $110.
However, uncirculated 1925-S peace dollars can be quite valuable. An MS-60 1925-S peace dollar is worth around $110, while an MS-65 1925-S peace dollar is worth around $250.
The most valuable 1925-S peace dollars are those that have been certified as proof coins. Proof coins are specially struck coins that are intended for collectors. They are typically made with a higher quality of metal and have a mirror finish. A proof 1925-S peace dollar is worth around $500.