The Atlanta city council may have gone relatively easy on the Falcons’ $300 million stadium subsidy demands on Wednesday, but the plan got a more skeptical response from an unexpected quarter yesterday: Invest Atlanta, the city’s economic development agency.

Board member Julian Bene questioned what the city would get for its money and argued that the new stadium would create only 600 or fewer permanent jobs — his admittedly informal calculation. Spending $500 million in hotel-motel taxes over 30 years for that number of jobs is “completely out of line” with what Invest Atlanta would typically do, said Bene, a longtime consultant for biotech pharmaceutical companies… “There’s no way we would ever spend half a billion dollars on a 500-job or 600-job operation,” he told Channel 2 Action News in a later interview.

Evaluating a project based on whether spending the same money on something else would get you a better bang for the buck — “opportunity cost,” in economic jargon — is absolutely an appropriat way of looking at stadium deals, and is pretty much never the way that elected (or unelected, for that matter) officials approach these decisions.

Fortunately for the Falcons, other members of Invest Atlanta stuck to the more customary script: Real estate executive Joseph A. Brown said that a stadium should be looked at as a way to help struggling neighborhoods, while city council member Cleta Winslow, who apparently isn’t on the Invest Atlanta board but showed up for the meeting anyhow, reiterated Wednesday’s line of thinking by saying that local communities aren’t saying no to a new stadium, “they are looking to us to see what we can extract out of this.” Because half a billion dollars for 600 jobs plus some promises that those jobs will go to local residents is so much better a rate of return.