House of Bones by Dale Bailey is a dollar on Amazon. This has one of the best premises of a horror novel I've ever read: A billionaire hires five strangers to spend two weeks in an abandoned, high-rise urban housing project that even gang lords and crack dealers avoid. It's basically The Legend of Hell House taking place in Cabrini Green.
I read the book when it first came out as a paperback nearly fifteen years ago. Unfortunately, I remember the book just not being very good. But I always remembered the premise.