Have you seen Kayla? Her clips are mostly what you're describing, using camera angles and the like rather than green screen effects. The majority of her files seem to be about 30 minutes, but she has some shorter ones and does mention that her prices are negotiable. I don't think 30 is a minimum length considering she has some that are 10 minutes, but it's worth a shot if you haven't already looked into using her.
http://clips4sale.com/studio/44749