I think we have established by now that the most important thing determining the value of a used crank is the size (and condition) of the journals.
Taking this thread sideways a bit now. How many have Nitrided their journals to extand crank shaft life. When Burlington carnks were available, the journals were Nitrided and mine have done a load of miles andare still fine for a $#!Tload more. To redon the bearings, I would need do no more than replace the inserts - job done. I have pondered if I do another engine, putting counter weights on a decent crank, grinding and Nitriding the journals, fit a harmonic balancer and inserts. I think that would be about as good as can be done. Has anybody else done it?
Surely, if a carnk had been Nitrided, it would be worth much more than one that has not.