The 1850-O Half Dollar is a common date and one which is usually priced as a "type" coin (though it carries a small premium in Mint State. Several dozen examples are known in Uncirculated condition, filling the PCGS CoinFacts with MS64 and better examples. Gems are exceedingly rare.
The strike on this date is often (usually) weak, a fact that is most visible on the obverse stars. Softness on the reverse is generally more uniform and loss localized. As with most coins, those that feature the strongest strikes should be worth a premium.