for  lightwave 
low res figure < 5000 polys
med 5,000 to 20,000
high <20,000
BUT  I would use subdivision surfaces on all these and likely at 3:1  so thats 15, 15-60 , and >60 thousand polys after subd.

In Poser you can use displacement maps to improve low and med res figures. Its a method game designers use to get real time displays.