The reason the estimate is so high is because of the boiler and running gear, which will have to be contracted out. Maynard Morris told me that the boiler needs about 2 million alone, one driving rod is bent, and if the drivers need latheing, well, you get the picture.
Yes, because all work is done by volunteers, the cost has been kept down considerably, and Maynard's incredible management has helped that. We'll just have to wait for the work on the boiler to start to find out the actual cost.
Other videos of the 223 restoration can be found at the ERA Films channel on Youtube as well.