To answer the original question is, clearly, NOT ENOUGH .
Barn finds seem to range from "take-it-away"to 1500. Commandos in unrestored (lower end machines may be highly molested), running condition seem to range bewteen 2000 and 5000. Pristine unmodified, well cared for examples with fresh paint and updated mechancals seem to range between 4000 and 10000; doing your own bike where you refurbush the engine, transmission, suspension and have the frame painted/powder coated and have the tank/sidecovers painted is a 10,000+ proposition; I have spent considerably more on each of my Nortons and my disease has just dragged a '76 R90s into its sphere; watch for the GDP of Germany to spike!
I have come to the conclusion that owning a Norton (insert name of virtually any motor vehicle) is a losing proposition, good thing they compete with sex for a good time...(at my age anyway :mrgreen:
If inflation gets a running start and my heirs manage to out live me they may break even when they sell off my roling stock.
Now if I had only purchased that 1967 427 Shelby Cobra for $6995 or one of the first original Colt Pythons for $225, or held on to my box of basball cards...
RS