Complex sentence: It was due to be rebuilt by the 2010--11 school year at a cost of over $80,000,000, until then the students were required to go to school at the local community college where they built trailers to add classrooms.
Split into simpler sentences: It was due to be rebuilt by the 2010--11 school year at a cost of over $80,000,000. Until then the students were required to go to school at the local community college where they built trailers to add classrooms.