How Much Is Too Much?

Sooooo as I sit here looking at my makeup collection I'm thinking to myself how much is too much makeup? I've had an on and off again relationship with makeup. Recently I just got back into it. With Q vendor presentations, youtube, bloggers and some makeup guru friends I am now actually having fun with makeup. I've tried stuff, found some holy grail products and stuff that is a no no for me. Now I have a nice collection but then I'm like I only have one face lol! I have given some stuff to friends and what not but how much is too much makeup for one person to have for personal use? Or is there such a thing lol!! What do you do with makeup that is still good but you just don't use anymore?