Complex sentence: Prof. Beyer in 1918 tried to get the government to buy it for the National Museum, but as the bullion exceeded 4,000 pesos (at the old rate), funds were not available.
Split into simpler sentences: Prof. Beyer in 1918 tried to get the government to buy it for the National Museum. But as the bullion exceeded 4,000 pesos (at the old rate), funds were not available.