Nothing perpetuates the art as investment hopes of the masses like, well, art as investment.
Hugh Grant has flogged the Andy Warhol portrait of Liz Taylor he bought in 2001 for $3.6m for $21m. That's 97% p.a. return.
Closer to home, a McCahon bought for $250 from Peter McLeavey in 1979 sold yesterday for a little over 500% p.a. return.