I began collecting this set many years ago, buying several from Dave Bowers of Empire Coin Company when the price was between ten and fifteen dollars and there was no distinction between PR60 and PR69 (at least to me).
The set includes many varieties, most dramatic being the 1868 and 1872 blundered dies with extra date punches in the rock below the gown. Many of the varieties have been described in publications by Kamal Ahwash, Walter Breen, Brian Greer, and most recently in Gerry Fortin's excellent on-line website at www.seateddimevarieties.com.
1858 is the rarest year followed by 1861 and 1862. In PR65 and better condition, 1862 is the rarest year due to the use of poorly prepared planchets.
Wayte Raymond's 1945 Standard Catalogue of United States Coins valued the 1861 and 1865 proofs at $7.50, higher than any other dates between 1860 and 1891. The 1873 and 1874 arrows proofs did not carry a premium. These values reflected the actual rarity of a given date.
Currently the arrows dates have a substantial premium while the 1861 and 1865 proofs have a relatively small premium due to the strong influence of type collectors.
Offered upgrades will be respectfully considered.