AntiTrumpAlliance

https://truthinamericaneducation.com/how-much-does-it-cost-to-build-a-school/

High schools tend to be the most expensive type of K-12 educational facility to construct, with costs ranging from $50 million to $100 million or more for a comprehensive institution serving around 1,500 students.

But I see what you mean, what I see online is all over the place. This might be telling - Maine is cheaper and tends to have smaller schools but check out the serious inflation in sq ft construction cost

• https://themainemonitor.org/improving-schools-expensive/

In 2015, it cost $270 per-square-foot to rebuild an elementary school. In 2017, it cost $313 and in 2018, $379. In 2023 the cost jumped to $491 and in 2024 reached $661. The cost of building middle and high schools in the state follows the same trend.