Green’s Dictionary of Slang

a mean, miserly person; also attrib.

1871		Galaxy (N.Y.) May 654: These Cheap Johns of villany have therefore hit upon an expedient which demands no skill, little labor, and less money.
1908		L.W. Payne Jr ‘Word-List From East Alabama’ in DN III:iv 298: cheap John, n. A niggardly or stingy person, one who does things in a cheap style.
1909		L.W. Payne Jr ‘Word-List From East Alabama’ in DN III:v 369: short John, n. Same as cheap John.
1914		T.A. Dorgan Indoor Sports 2 Aug. [synd. cartoon] Waal, I swan!! So that’ s the millionaire she’s been telling us of, eh — Looks like a cheap john to me.
1948		J. Evans Halo For Satan (1949) 49: I talked to that crummy landlady and her cheap-john roomers.
1952		W.R. Burnett Little Men, Big World 179: The girl raises a big commotion about what a cheap-john this sucker is, trying to get out without paying.