Thanks for the heads up guys, I went down to Supergas for a winge today and ended up speaking to the sales manager on the phone while at the counter. He ended up giving me a 10.5m3 refill for $125, less than half what I was paying.
I don't have pics of the damaged manifolds, one I had to repair, and one I saw on a car, the crack was definitely down in the webbing but it could have started beside the weld and cracked further away as it made it's way around the pipe. I didn't get a good look at it as it was on the car. It was probably 2mm tube so very thin and light stainless. It would glow white hot on the dyno within a second or two of hitting boost. My point was, he had a GT42 mounted without a hanger or support, and a 4 inch exhaust with no hangers till the diff. Perhaps it would have lasted longer if the manifold could move around on the head a little and the turbo was supported.