If that's $343 USD, that must be a new crankshaft since it's pretty expensive.
Seriously, ask at
www.redpepperracing.com, you can probably find one there for around $75.
These crankshafts usually don't go bad unless the motor spun a bearing, so you will be fine with a used crankshaft. A little polishing of the journals by a machine shop and a used crank will be as good as new.