The California Department of Consumer Affairs' position is that paint has a two year lifespan and the cost of repainting after a stay of less than that period should be pro rated accordingly. However, it is also their position that holes in the walls or ceiling that require filling with plaster, or that otherwise require patching and repainting, could justify withholding the cost of repainting from the tenant's security deposit.

http://www.dca.ca.gov/publications/l...-deposit.shtml

$450 to repaint a bedroom is not unreasonable. It recently cost me $1,500 to repaint an entire apartment, and I only got that price because the carpet was being replaced, so the painter could spray and not worry about damaging the old carpet.