That's OK. These books are nearly becoming investment grade.
I've got a majority that don't have much resale value, but some of them have gone absolutely nuts - 2 - 4X even used with wear over what I paid as a new copy.
My personal favorite (that I was a contributor for) is Walt Casler's "Allegheny Valley Logging Railroads" (softcover), that had a price of $12 in the original year of publication - 1976(?) and now is on Amazon, used, for $162.