I’ve never been sure that he’s as different from the rest as he’s been painted, though. And the most damning evidence against him that I’ve seen is this letter in the Guardian signed by 40 economists, in support of his views. As they kindly point out, much of what he says on economic policy is actually mainstream economic theory rather than extreme or different; it’s simply that the Tory/Labour/media consensus in the UK has bought in to a different strand of economic theory. They’re the extremists, rather than Corbyn.
Trying to make capitalism work a little better for more people, which is basically what he seems to mean by opposing austerity economics, is an entirely worthy aim in itself. It isn’t the same thing, though, as proposing an alternative economic vision.