Complex sentence: Problems arose when it became obvious to the movies Producers that filming at Pinewood Studios, or anywhere in the UK would be too expensive so other alternatives were explored, the best of which seemed to be an offer from the Argentinian Government.
Split into simpler sentences: Problems arose when it became obvious to the movie's Producers that filming at Pinewood Studios, or anywhere in the UK would be too expensive. Other alternatives were explored, the best of which seemed to be an offer from the Argentinian Government.