With an enrollment of ~3,000, each $10 million adds more than $3,300 to the real cost per ADA. State debt service, "on-behalf " of the District, for matching grants funded by state bonds, adds to the cost per ADA, as does the state's subsidy "on-behalf" of the Districts for unfunded accrued liabilities(UAL's) in CalSTRS and CalPERS pensions and benefits.
The real cost per ADA will exceed $20,000 in a few short years.
With teacher's compensation already among the highest in the state, the district is re-negotiating a contract into a likely retroactive pay raise. I guess they really didn't need the parcel taxes.