Polygon budget for 5 characters in an iphone app

Hi all, first off - Im a noob seeking advice - full disclosure. I've been through 4 tutorial books for Unity and have been having pretty good luck so far. I am planning on making a foray into the ios world (iphone) with a small app that is simply 5 human figures, stumbling around a small and very simple court yard.

As I begin to model this scene up - what should I budget for polys for each character? I want to give them as much detail as possible w/o bogging down the scene. I realize all aspects of the scene must be considered (textures, drawcalls etc) but If you could just point me in a conservative direction so I won't have to go back later and adjust the models. Thanks for any suggestions Jinda