Not sure what a new crank would cost, or even a used one... but grinding/polishing the journals, magnaflux and balance is going to be over $200.
I know they weld up journals... it *might* be cheaper to have the snout welded up/ground to size.
But if your current crank is at the higher side of wear (.040 or .050 under) I would get another. If STD or .020 under I might repair if the cost was similar.
