You would think so.
However, I'd have predicted that the bubble would burst eventually on BSA Gold Star DBD34s, Kawasaki Z1s and FS1Es as the age increased and the disposable income of their respective nostalgista decreased.
However, economics is always about the allocation of resources that have alternative uses, and people just keep coming up with different excuses to buy them, have them and covet them, which means that the supply v demand curves are always skewed towards a seller's market.
If I could predict this sh!t I'd be a richer person than I am. I can't but all the signs presently point to Cubs (as in made-in-Japan-by-Honda Cubs) continuing to rise in price, at least for the foreseeable future.