Complex sentence: The initial estimated cost for building this new city was 40 million Belize dollars (20 million U.S. dollars), however, only 20 million Belize dollars (10 million U.S. dollars) were available, but the momentum was not to be lost.
Split into simpler sentences: The initial estimated cost for building this new city was 40 million Belize dollars (US $20 million). Only 20 million Belize dollars (US $10 million) were available, but the momentum was not to be lost.