That new box is at Usher Enterprises 503-647-0015 @ $175. They make to order and it takes a couple days and will ship for the same price.
If it's a legal box, that's actually a fair price.
I repaired the air-box on my plane with a kit from McFarlane several years ago. The kit itself cost $50 or so. But, I had to use a torch to remove the butterfly from the old shaft, clean and straighten the box, MIG-weld the new bushings in place, then paint everything when done.
It came out pretty good (my A&P thought so); But for the time and effort, buying the ones above would've been worth it.
