The short story
The Experience Machine: A Metaphysical Horror by Jason Werbeloff is free, probably today only. I have read this myself, and like much of Werbeloff's works, it's good but also a bit disturbing. It's the kind of story that tends to stick with you for a
long time afterward. Still, I highly recommend it and pretty much everything I've read of Werbeloff's. This is much more science fiction than horror, despite the full title.