Gallery Press GP102 Mentor MD130 Lion Library LL6 Belmont 90-286
As a general rule of thumb, short story anthologies are not particularly valuable. The exception, of course, is if the book contains an original story by a now-collectible author.
Gallery Press GP102 (published in 1973) contains FIVE original stories by Edward Wood, Jr ... under his own name! (Wood was a notorious user of multiple pseudonyms.)
Mentor MD103 is a double-hitter. It contains the first recorded story by Jack Kerouac (a previously published magazine article under the pseudonym Jean-Louis). Also present is a story by Joseph Heller: a chapter from his yet-unpublished novel Catch 22, once again released previously in a periodical.
Lion Library LL6 lists numerous great authors on the cover ... but it's important to collectors for the author that isn't listed: Jim Thompson and his short story Time Without End.
Belmont 90-286 is a compilation of stories by Charles Willeford, one of the most-collected authors by vintage paperback advocates.