The most difficult color combination features a red infield--these are rarely seen although Lew Lipset had a few in his 2010 auction. This one went for over $4K, and the others went for similar $$$:
The next most difficult colors go for far, far less money and include the purple pennants/green bases group and yellow pennants:
Those who collect these can give you better guidance on what's next in terms of difficulty, but I always thought these were slightly more difficult than the remaining:
Those that you won are of the most common variety, along with the blue infields, which I do not like because its hard to read the player name:
Finally, the only player that I'm aware of who is more difficult to find is Kavanagh, corrected from the more commonly seen Cavanaugh, although still incorrectly spelled with a "u".
EDITED TO ADD another common combination:
