AbeBooks has searched its vaults to come up with 30 beautiful cover designs from a century ago (give or take a few years).
Most of the books are available for somewhere between 50 and 200 dollars. One notable exception is Pauline E. Hopkins’ Contending Forces, which the site describes as:
the eighth published novel by an African American woman, and one of the most important, notable for its realistic portrayal of lynching and prejudice in the unreconstructed South. Additionally, this was only the third novel published by an African-American-owned publishing company.
A first edition from 1900 is going for $9,500. For those of us with more realistic budgets, a lot of other copies are available, starting at $2.72 (plus shipping).