I thought about doing that Dave but I don't think it would be cost effective. I believe a new shaft is about $90 and then there would be gaskets and seals to buy. I've never replaced a crank on a mower but I've done it on a car engine. Not a fun job.
I think I'd end up with more money and timemoney in it than $200.
If it is... or was as good as the Snapper Ninja I have then its a shame to part it. I'm really impressed with the Ninja. I've thought about keeping it.