Opportunity costs

If passed, the Oak Park Measure R bond would cost residents $44.87 per $100,000 of assessed value for 30 years.

In addition, residents have three other school taxes they are paying: a 1970s facilities bond, a technology bond and a parcel tax.

•$40-million 1977 bond: $115 per $100,000 of assessed value, spikes to $193 in 2009, drops to $89 in 2010, and decreases each year to about $50 in the final year, 2016.

•$17.5million technology bond: $24 per $100,000 of assessed value, passed in 2006 and runs for 25 years. The bond is paying for upgrades to the district's computer labs, wireless technology, network infrastructure and teacher training.

•Measure C parcel tax: $197 per home per year. Renewed in 2007 for eight years and pays for academic programs, instructional materials and teacher salaries.