The one catch is that these types of things typically need to be in really good shape.
I recently sold a 1965 Honda Trail 90. In pristine condition it would have been worth thousands.......(perhaps more than $10k).
In the hammered condition mine was in.............even though it had all its original parts...........it was worth a few hundred. Not bad, but had I kept it indoors for 20 years I owned it instead of in the garage, things might have been much different.