0.010 bearings do cost a bit more. I seem to remember it was less than $100 more than standard bearings. The 0.020 bearings are expensive, when you can find them.
I'm the guy who had the broken crankshaft that had been turned down 0.010 with about a year of flying on it before it broke. It may have been that turning it down exposed a flaw (all steel contains flaws), it may have been turned improperly, or it may have suffered a prop strike that stressed it sometime in its life.
I would think the best bet is to buy a new crankshaft. It will have plenty of rebuild life on it and should be a "known" quantity. The second best bet is to buy a used crankshaft that has been serviced by a well known shop (the broken one I had wasn't). I would be reluctant to buy an eBay crank from an unknown seller, since you wouldn't know if the yellow tag had been forged or something.
That being said, I bought a used 0.010 crankshaft for my rebuild. It was a fresh turn from Rick Roman's and the seller was an FBO with a good reputation. I shopped for new crankshafts in Trade-A-Plane, but they all required I turn in a core (which I didn't have). The price without a core was crazy. I'm a little curious what would happen to a core. Does it get turned into a "new" crankshaft with dubious history somehow?
