Since when has buying a motorcycle ever been an exercise in good and rational judement? Who cares if it takes $20K to fix the damn thing. If the guy has the means and is willing to do what it takes to make it right "for him" more power to ya.
There is an invaluable component to owning anything, much less a motorcycle, that you have personally ressurected from death. The knowing that this project, if and when completed, was accomplished by oneself, and ever last little item that makes its existence possible has been touched, felt, examined, understood and assembled by the owner will have a meaning that no one but them will comprehend. Put a price tag on that.
What's the Buddhist saying..."to journey well is better than to arrive" or something like that. Hell I would have bought the thing just for the challenge.
I'm with MIXR, Good on ya mate. Now get busy and let's see some progress pics.