If you're comparing dollar value, then you'll need to compare relevant quantities there though. "hundreds of dollars more per year" over several decades is tens of thousands of dollars.
What is the relative expense of "section 8" than public housing, since it doesn't produce better economic outcomes than public housing?
But like you mention, there are other axes of evaluation, such as fighting segregation, classism, etc., in addition to basic social justice. "Market soultions" are quite (most?) often the best solutions along these axes, but being a market solution is not an end within itself, IMHO.
This study is just one tiny aspect of the big picture. But its still worthy of publicizing because it's not what I, or many others, expected.