Maynard and Sims have a few books on sale at Amazon. I have several of these in paperback from the old Leisure book club. But I haven't read any of them yet.
Demon Eyes is $1.49: Girl goes to party at a secluded mansion. Kooky things happen.
Black Cathedral is $0.99: At an old manor house on a remote Scottish island, six managers of a large corporation arrive for a week-long stay. Within days they will all suffer horrifying deaths and their bodies will never be found. The government assigns the case to Department 18, the special unit created to investigate the supernatural and the paranormal.
Night Souls is $0.99: Department 18 takes on the Breathers, the species of psychic-sexual vampires from Demon Eyes, and gets caught between warring factions—one wants to coexist peacefully with humans and the other wants only to feed off them until humanity is wiped out.