Standardized testing is quite the piñata these days, and one of the sticks being wielded most often to batter the assessment industry is its sheer size—$1.7 billion a year, by one oft-cited estimate.

The author of that figure, Matthew Chingos of the Brookings Institution, recently objected to what he sees as the constant misuse of his calculation, arguing that the dollar total isn’t nearly as daunting as it seems.

Chingos, as he explained in a recent blog post, came up with the estimate of what states spend on testing in 2012 as part of a report in which he looked at the size of states’ contracts with individual assessment vendors—Pearson, the American Institutes for Research, the Data Recognition Corp., and so on.

In that report, the Brookings senior fellow obtained figures from contracts in many states at various grade levels, which brought him to a $669 million testing toal, and then reached the $1.7 billion figure based on a projection of costs across states and exams that were not in his initial calculation.

His totals didn’t include the costs of myriad formative assessment and other exams given at the district level at the discretion of administrators, and in some cases individual teachers.

That localized testing is an industry unto itself. One recent examination found that more tests are required at the district, rather than state level, but that contrary to popular opinion, less than 2 percent of classroom time, overall, is spent on assessment.

Teachers’ unions and others have used the nearly $2 billion-per-year state figure to argue that K-12 policymakers’ priorities are askew, and that the money being pumped into exams could instead be channeled into other, more holistic approaches to teaching, learning, and measures of academic progress.

But what the testing critics often overlook, Chingos says, is that spending on testing is just a fraction of the overall amount spent on K-12 education—just one-quarter of 1 percent of that larger total of nearly $600 billion annually.

Roughly a decade before Chingos’ report was published, a separate estimate he cites by the Pew Center on the States and researcher Caroline Hoxby put test-makers’ revenue in a single year at $315 million, or .06 of per-pupil spending.

Ultimately the costs of sustaining K-12 public education are so great that cutting the $1.7 billion testing pricetag won’t buy the nation much, he notes.

Pouring savings from state testing into teacher salaries, for instance, would raise pay 1 percent. Student-teacher ratios could be cut by the equivalent of .1 students, he estimates.

Thus, abandoning annual testing would be “penny-wise and pound-foolish,” Chingos contends. He also notes that those who hate cookie-cutter “bubble tests,” but also bemoan the money devoted to testing need to acknowledge that moving to more sophisticated forms of assessment will jack up the costs of assessment.

Standardized testing has come under a fresh wave of vitriol in the era of common-core testing. But how has the common-core, and the work of the two main consortia that designed exams for use by states, altered state spending?

Probably not much, Chingos said in an interview. That’ s because the per-student testing costs estimated by the Partnership for Assessment of Readiness for College and Careers, and the Smarter Balanced Assesment Consortium, are roughly in line with what many states were paying in the pre-common core days. By collaborating, states could save money over time, though how much is hard to predict.

(If you’re interested in another take on how the common-core has shaped the testing industry, see my recent breakdown of which testing companies enriched themselves by winning their share of $360 million in combined contracts doled out by the two common-core consortia.)

The Brookings researcher doesn’t sound like he expects his argument about the costs of testing to change the minds of many. In fact, as the debate over the role of tests plays out in Congress, and in individual states and districts, much of the focus has turned to what stakes the results of those exams should carrry—not their pricetag.

Already, Chingos said, “a  lot of the conversation has moved beyond costs.”