I have been a fan and collector of the Ars Longa 19th century Detroit cards.
I hold myself to a budget limit as some of the cards command a healthy premium. Check out Sam Thompson, for example, I'm patiently waiting for one within my budget.
http://arslongaartcards.com/series/beginnings-1880s/
I like them and will continue to pursue them. I do not collect them with expectation to profit but instead to enjoy them for what they are, well done color depictions of the players I enjoy.