[Got Insulin?]

In my experience, the 75/50% concept has always been the rule of thumb for internet pricing of most of your common car parts with things like wheels and some other miscellaneous categories being obvious exceptions, so Yellow is about spot on.

You'll take a loss mostly because most people won't want to take a chance that you mishandled the crank in some way, but partially because strokers of any variety often cost a fair amount in machine work as well. Buying good parts cheaply is the name of the game for most of us. It just is what it is, man.