Thomthom's Model Info gives you certain amount of info about your model but not sure if it lists per item.
AdamB's Goldilocks v2 indicates hi-poly object based on view. So if you have a hi-poly cup 20' from view it'll indicate it.
Fredo has a Triangle count tool but I forget the name.
I don't think there's something that does exactly what you want. But I could be wrong.... π