The Predator (apart of being completely idiotic) was at least funny at times, Ive bought it cheap 3 years after theatrical release. Prey was boring, unengaging, cheap looking and I didnt care for any of the characters. I may buy it too eventually, but I can live without it.
That being said, I really hate the fact that streaming movies are not released on Blu-ray (Greyhound is the one I would really like to put on my shelf).