Collectables usually fail the "common enterprise" prong of the Howey test. Unless the operator is manipulating the market. Then, trouble. "In a fraudulent business scheme based upon the secret and dramatic manipulation of collectible stamp values, Escala and its former CEO, Manning, violated the antifraud and reporting provisions of the Exchange Act...."[1]

[1] https://www.sec.gov/litigation/complaints/2009/comp20965.pdf