1829 Dimes are found with several different reverses: Small 10C, Medium 10C, Large 10C, Small 10C over Large 10C, and Extra Large 10C. PCGS recognizes the first four as major varieties, the last one as a die variety (JR-1).
Though mnost price guides value the Small, Medium and Large 10C almost equally, there is a big difference in rarity among the three. The Small 10C is the most common by a factor of almost 10 to 1 (based on the November 2011 PCGS Population Report). The Large 10C is roughly twice as scarce as the Medium 10C.
PCGS has certified only eight Mint State examples of the 1829 Large 10C Dime. Of those, the finest is a single PCGS MS67.