This is one idea I've forgotten to include simply because it was so obvious. Previously I discussed online charter schools, which have especially low costs due to their unique education model. But what about "regular" charter schools? If you're not familiar with the concept, you can read lots of details at http://www.uscharterschools.org/pub/uscs_docs/index.htm. But basically, a charter school is an independently-run school (like a private school) that, based on certain agreements with the board, becomes part of the public school system, enabling parents who could not otherwise afford private schools to take advantage of alternative educational models. And since attendance at charter schools is 100% by free choice, a charter school that does not offer quality education will automatically be shut down as the students and parents "vote with their feet", unlike traditional public schools. A robust system of charter schools in Hillsboro would provide real choices for families not currently being served by the neighborhood schools.
So, charter schools may be nice, but why would they save money? As you may have heard, a district is only required to give charter schools 80% of its per-student funding for each student that attends. But it's actually even less than that: if you look closely at the budget, various parts of it are in special buckets that "don't really count" as per-student spending, by some judgements. (Construction bond repayment, etc.) So if you actually look at the total district expenditure divided by the total number of students, charter schools receive significantly less than 80% of what the district spends per-student. This means that the more students in charter schools, the more the district saves. Because they only gain money to the extent that voluntary customers choose their schools, charter schools have much greater incentive than traditional public schools to find efficiencies and increase quality at lower cost.
Of course, the fewer students in the traditional non-charter schools would mean that there might be some teacher layoffs-- but the loss of demand for teachers in public schools would be balanced by increased demand for teachers in the charter schools, so for each teaching job lost, one would likely be created. Experienced teachers should easily remain employed, and the loss of students to charter schools might well be the wake-up call the current schools need to improve their own efficiency and quality.