The1871-S Half Dollar had the largest mintage of any S-Mint Half Dollar up to that date and the largest mintage of any Half Dollar since 1861. Nonetheless, it is generally priced at a small premium over the regular "type" coins, including those of the 1880's with smaller mintages. It is relatively scarce in Mint State, with the average grading hovering in the MS62 to MS64 range. Gems are very rare.
The strike quality on the 1871-S Half Dollar is usually quite good. Luster, as seen on the few Mint State examples we've encountered, is frosty.