Both figures are BS. Coal plant scrubbers can cost hundreds of millions each plant. With something like 900 affected plants across the east, no way I believe the price tag is only a couple billion.
As for the hundreds of billions in health benefits, well...this smells like the millions of jobs that have been "saved" under BO's reign of terror: pure fiction.
Note that the cost given was just for next year. IIANM, most of the implementation costs come in the second phase, about 5 years down the line.