Using Chroma Key To Save Location And Transport Costs?

Hello guys,

What do you think about the idea of using the chroma key technique for the background of every single shot in one's movie?  That way you save on location and transport costs, and you can set your movie in any location - all you need is a set of pictures or video clips from each location.  You can set your movie anywhere in the world without having to travel there with your actors.  You get to shoot all your movies in one location - the green screen set.

Big budget like Star Wars and 300 are often shot this way but I've not heard of many low budget movies that are shot this way.  What are the potential setbacks of such an approach and is it worth trying?  Why don't more people use it?

I look forward to responses that will shed more light on the issue.  Thanks.

. . . and you'ld need professionals in that regard. . .which I don't think we have the luxury of, here in Nigeria I mean. .

i think is a good ideal but what they need now is a set-designer