The high per-pupil cost probably has nothing to do with Special Needs. I couldn't find a perfect indicator for this, so I looked at support services and state aid as guideposts.

Millburn spends about $100 less per student on Support Services (3227pp v. 3327pp) and Madison a little less (3161 pp) [NJ Taxpayers Guide To Ed Spending]. These are good examples since not only are the dollar amounts close but Madison and Millburn both have a higher percentage of Budgetary Cost PP for Support Services (18% and 17.6%, respectively) than Berkeley Heights (16.7%). Madison receives a similar amount to Berkeley Heights in State Aid (2.2M and 2.1 M, respectively), while Millburn receives 4.3 Million [NJ State Aid Summaries].

Considering these facts, consider the total per pupil cost for each District.

Millburn ~ 18k per pupil 3rd on the list in connection to ratings and ranking

Madison ~ 17k per pupil 7th on the list in connection to ratings and ranking

Berkeley Heights ~19k per pupil 20th on the list in connection to ratings and ranking

Of course, I could be using incomplete indicators concerning Special Needs, but these are the best I can find. 

So it's not OPRA, it's not teachers, and it doesn't look like it's special needs either.

 We have apparent things we know we are spending money on that do not make sense (Central Administration, Legal Fees), and our Budget process is broken.

References:

Further Reading:

04/23/2023 Post on Ratings and Rankings (bit.ly/41KbfQE)

04/23/2023 Note on Median Salaries (bit.ly/40Cl0PH)

04/24/2023 Follow up on Median Salaries (bit.ly/3oDac6L)