What Has Happened to the Price of Japanese Classics?

Certain Japanese classic motorcycles have increased by 180% to 200% since March 2012. Is this an anomaly, is it a bubble or is this the beginning of an explosion I have predicted in emerging market classic motorcycles? I sold a Honda CB750K0 to Cz...
http://www.themotorcyclebroker.co.uk/what-has-happened-to-the-price-of-japanese-classics/