Bonsai is an art form that requires years of training and centuries of dedication. At the 2012 international bonsai convention, a tree was on sale for 100 million yen, just under a million dollars.

David A. King, Tree Form, Height Growth, and Susceptibility to Wind Damage in Acer Saccharum, Ecology, Vol. 67, No. 4 (Aug., 1986), pp. 980-990 ...