Secondhand computers are one way to bridge the gap. Some dealers provide multiyear warranties that limit risk.

And the rise of Web-based applications-which shift heavy-duty computing work to powerful, off-site servers-means schools can get away with units that feature less horsepower, Krueger says.Dan Schmidt, technology director for the 3,500-student Lake Geneva-Genoa City Union High School District in Genoa City, Wis., took the plunge this summer. He bought a test batch of five Dell desktops from CDI Computers of Toronto and was impressed. Now he has 350 units—and estimates his savings at 40 percent over new equipment.

For district's like Schmidt's, refurbished computers are emerging as a win-win solution in tight budget times, satisfying both tech-hungry students and budget-conscious administrators.