Ron Guth:
The 1902-O Dime has a seemingly large mintage of exactly 4.5 million coins, but they were either ignored by collectors or the coins had a hard time getting from New Orleans to the collectors in the North. As a result, high-grade examples can be pricey. In most circulated grades, the 1902-O Dime commands only a small premium, but in AU and better grades the price jumps quickly. Mint State examples are scarce but not rare. The most frequently-seen Mint State grade is MS64. Gems are very rare and anything above MS66 is nearly impossible to find.
The best example of a 1902-O Dime (and a colorful one, to boot) is the NGC MS67 from the John Jay Pittman and Eugnene Gardner collections. Coincidentally, that piece has the record price of $12,650 for the date.