Does anyone know of any good (and more importantly CHEAP) stock footage libraries where you can get stuff that would be difficult/expensive to shoot (eg fire, deserts, wild animals, outer space, foreign locations etc etc etc). I know places like Getty Images and The Telegraph have footage libraries but are ridiculously expensive.

I suppose 'borrowing' stuff from TV or other films would be one idea but a little risky if found out?

Any suggestions appreciated...