If they don't have the budget for quality fx, and realistic picturesk scenery then don't try. Please don't put actors infront of a really horriblly obvious green screen.
also if u don't have the budget for quality realistic computer generated dinosaurs then you have other ways to convey the same intent. audio, camera angles can net you the same terror if you are smart about it without putting a huge crappy fake evil dinosaur cropped onto the screen.
Its visuals, audio, acting, and plot was more like a crappy syfy movie...and I wanted it to be like Lost (in the acting, camera visuals, and plot)